diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 6dce3d64..dbc87aff 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -82,7 +82,7 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     needs: build
-    if: github.event_name == 'release' || (github.event_name == 'workflow_dispatch' && github.event.inputs.publish == 'true')
+    if: github.event_name == 'release' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && github.event.inputs.publish == 'true')
     timeout-minutes: 15
     permissions:
       id-token: write
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 34f7b387..a971ef43 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -322,7 +322,7 @@ jobs:
           prompt-file: /tmp/prompts/prompt-1.txt
 
       - name: Save pass 1 response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_pass1.conclusion == 'success'
         run: |
           cp "${{ steps.ai_pass1.outputs.response-file }}" /tmp/pass-1.txt
           sleep 65
@@ -338,7 +338,7 @@ jobs:
           prompt-file: /tmp/prompts/prompt-2.txt
 
       - name: Save pass 2 response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_pass2.conclusion == 'success'
         run: |
           cp "${{ steps.ai_pass2.outputs.response-file }}" /tmp/pass-2.txt
           sleep 65
@@ -354,7 +354,7 @@ jobs:
           prompt-file: /tmp/prompts/prompt-3.txt
 
       - name: Save pass 3 response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_pass3.conclusion == 'success'
         run: |
           cp "${{ steps.ai_pass3.outputs.response-file }}" /tmp/pass-3.txt
           sleep 65
@@ -370,7 +370,7 @@ jobs:
           prompt-file: /tmp/prompts/prompt-4.txt
 
       - name: Save pass 4 response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_pass4.conclusion == 'success'
         run: |
           cp "${{ steps.ai_pass4.outputs.response-file }}" /tmp/pass-4.txt
           sleep 65
@@ -386,7 +386,7 @@ jobs:
           prompt-file: /tmp/prompts/prompt-5.txt
 
       - name: Save pass 5 response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_pass5.conclusion == 'success'
         run: |
           cp "${{ steps.ai_pass5.outputs.response-file }}" /tmp/pass-5.txt
           sleep 65
@@ -402,7 +402,7 @@ jobs:
           prompt-file: /tmp/prompts/prompt-6.txt
 
       - name: Save pass 6 response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_pass6.conclusion == 'success'
         run: |
           cp "${{ steps.ai_pass6.outputs.response-file }}" /tmp/pass-6.txt
           sleep 65
@@ -446,7 +446,7 @@ jobs:
           prompt-file: /tmp/prompt-merge-a.txt
 
       - name: Save merge-A response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_merge_a.conclusion == 'success'
         run: |
           cp "${{ steps.ai_merge_a.outputs.response-file }}" /tmp/merge-a.txt
           sleep 65
@@ -479,7 +479,7 @@ jobs:
           prompt-file: /tmp/prompt-compress-a.txt
 
       - name: Save compress-A response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_compress_a.conclusion == 'success'
         run: |
           cp "${{ steps.ai_compress_a.outputs.response-file }}" /tmp/compress-a.txt
           sleep 65
@@ -523,7 +523,7 @@ jobs:
           prompt-file: /tmp/prompt-merge-b.txt
 
       - name: Save merge-B response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_merge_b.conclusion == 'success'
         run: |
           cp "${{ steps.ai_merge_b.outputs.response-file }}" /tmp/merge-b.txt
           sleep 65
@@ -556,7 +556,7 @@ jobs:
           prompt-file: /tmp/prompt-compress-b.txt
 
       - name: Save compress-B response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_compress_b.conclusion == 'success'
         run: |
           cp "${{ steps.ai_compress_b.outputs.response-file }}" /tmp/compress-b.txt
           sleep 65
@@ -641,7 +641,7 @@ jobs:
           prompt-file: /tmp/prompt-final.txt
 
       - name: Save final merge response
-        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true'
+        if: steps.tag_check.outputs.exists == 'false' && github.event.inputs.skip_ai_notes != 'true' && steps.ai_merge.conclusion == 'success'
         run: cp "${{ steps.ai_merge.outputs.response-file }}" /tmp/final-merge.txt
       - name: Write release notes to file
         if: steps.tag_check.outputs.exists == 'false'
diff --git a/build/Package.props b/build/Package.props
index d521d115..a1c7caa8 100644
--- a/build/Package.props
+++ b/build/Package.props
@@ -4,7 +4,7 @@
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <LangVersion>default</LangVersion>
-        <PackageVersion>5.1.3-alpha2</PackageVersion>
+        <PackageVersion>5.1.3-alpha2-fix</PackageVersion>
         <Authors>Dmitry Zhutkov (Onebeld), Andrey Savich (pieckenst)</Authors>
         <Copyright>Dmitry Zhutkov (Onebeld)</Copyright>
         <PackageTags>theme, design, xaml, library, ui, gui, control, csharp, styled-components, interface, dotnet, nuget, style, avalonia, controls, user-interface, styles, avaloniaui, pleasant, graphical-user-interface</PackageTags>
diff --git a/samples/PleasantUI.Example/MainView.axaml.cs b/samples/PleasantUI.Example/MainView.axaml.cs
index 8e9e0ef1..551e4766 100644
--- a/samples/PleasantUI.Example/MainView.axaml.cs
+++ b/samples/PleasantUI.Example/MainView.axaml.cs
@@ -83,6 +83,10 @@ private void OnNavigationSelectionChanged(object? sender, SelectionChangedEventA
         // stays visible, without going through SelectionChanged again.
         MainNavigationView.SelectionChanged -= OnNavigationSelectionChanged;
         MainNavigationView.SelectedItem = HomeNavItem;
+        // HomeNavItem must not appear highlighted while a leaf page is active.
+        HomeNavItem.IsSelected = false;
+        // Re-highlight the leaf item — SelectSingleItemCore cleared it when we redirected to HomeNavItem.
+        selected.IsSelected = true;
         MainNavigationView.SelectionChanged += OnNavigationSelectionChanged;
     }
 
diff --git a/src/PleasantUI/Controls/NavigationView/NavigationView.cs b/src/PleasantUI/Controls/NavigationView/NavigationView.cs
index f533188d..1a606f06 100644
--- a/src/PleasantUI/Controls/NavigationView/NavigationView.cs
+++ b/src/PleasantUI/Controls/NavigationView/NavigationView.cs
@@ -1,4 +1,5 @@
-using System.Runtime.InteropServices;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
 using System.Windows.Input;
 using Avalonia;
 using Avalonia.Animation;
@@ -52,6 +53,10 @@ public class NavigationView : TreeView
         
     private ILogical? _logicalSelectedContent;
 
+    // Stores the IsExpanded state of group items before the pane collapses to compact mode,
+    // keyed by the NavigationViewItem instance so each item's state is tracked independently.
+    private readonly Dictionary<NavigationViewItem, bool> _expandedStates = new();
+
     /// <summary>
     /// Defines the <see cref="Icon" /> property.
     /// </summary>
@@ -380,6 +385,7 @@ static NavigationView()
     {
         SelectionModeProperty.OverrideDefaultValue<NavigationView>(SelectionMode.Single);
         SelectedItemProperty.Changed.AddClassHandler<NavigationView>((x, _) => x.OnSelectedItemChanged());
+        IsOpenProperty.Changed.AddClassHandler<NavigationView>((x, e) => x.OnIsOpenChanged(e));
     }
 
     /// <summary>
@@ -397,18 +403,20 @@ public NavigationView()
     /// <inheritdoc />
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
+        Debug.WriteLine("[NavigationView] OnApplyTemplate");
         base.OnApplyTemplate(e);
 
         _stackPanelButtons = e.NameScope.Find<StackPanel>("PART_StackPanelButtons");
         _headerItem = e.NameScope.Find<Button>("PART_HeaderItem");
         _backButton = e.NameScope.Find<Button>("PART_BackButton");
         _contentPresenter = e.NameScope.Find<ContentPresenter>("PART_SelectedContentPresenter");
-
         _container = e.NameScope.Find<Border>("PART_Container");
         _mainGrid = e.NameScope.Find<Grid>("PART_SplitViewGrid");
         _dockPanel = e.NameScope.Find<DockPanel>("PART_ItemsPresenterDockPanel");
         _marginPanel = e.NameScope.Find<Border>("PART_MarginPanel");
 
+        Debug.WriteLine($"[NavigationView] OnApplyTemplate parts: headerItem={_headerItem is not null} backButton={_backButton is not null} contentPresenter={_contentPresenter is not null}");
+
         if (_headerItem != null)
         {
             _headerItem.Click += (_, _) => IsOpen = AlwaysOpen || !IsOpen;
@@ -423,7 +431,7 @@ protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
         if (TopLevel.GetTopLevel(this) is PleasantWindow window)
         {
             titleBarHeight = window.TitleBarHeight;
-
+            Debug.WriteLine($"[NavigationView] OnApplyTemplate PleasantWindow found titleBarHeight={titleBarHeight}");
             UpdateMacNavigationLayout(window);
             UpdateContainerTitleHeight(window);
         }
@@ -434,12 +442,13 @@ protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     protected override void OnLoaded(RoutedEventArgs e)
     {
         base.OnLoaded(e);
+        Debug.WriteLine($"[NavigationView] OnLoaded itemCount={Items.Count} firstItem={(Items.Count > 0 ? (Items[0] as NavigationViewItem)?.Header : "none")}");
 
-        // Hack. For some reason it does not highlight the first item in the list after running the program
         if (Items.Count > 0)
         {
             if (Items[0] is ISelectable selectableItem)
             {
+                Debug.WriteLine($"[NavigationView] OnLoaded selecting first item header={(selectableItem as NavigationViewItem)?.Header}");
                 SelectSingleItem(selectableItem, false);
             }
         }
@@ -449,15 +458,18 @@ protected override void OnLoaded(RoutedEventArgs e)
     protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e)
     {
         base.OnAttachedToLogicalTree(e);
+        Debug.WriteLine($"[NavigationView] OnAttachedToLogicalTree itemCount={Items.Count}");
 
         if (Items.Count > 0 && Items[0] is ISelectable selectableItem)
         {
+            Debug.WriteLine($"[NavigationView] OnAttachedToLogicalTree selecting first item header={(selectableItem as NavigationViewItem)?.Header}");
             SelectSingleItem(selectableItem);
         }
     }
 
     internal void SelectSingleItem(ISelectable item, bool runAnimation = true)
     {
+        Debug.WriteLine($"[NavigationView] SelectSingleItem header={(item as NavigationViewItem)?.Header} runAnimation={runAnimation}");
         // Always run deselection of other items, even if this item is already selected
         CloseAllSubMenuPopups();
         SelectSingleItemCore(item, runAnimation);
@@ -498,18 +510,24 @@ private void UpdateMacNavigationLayout(PleasantWindow window)
 
     private void UpdateContainerTitleHeight(PleasantWindow window)
     {
-        if (_container == null)
-            return;
+        if (_container == null) return;
 
-        // Determine margin based on custom title bar setting.
         Thickness margin = window.EnableCustomTitleBar ? new Thickness(8, titleBarHeight + 1, 8, 8) : new Thickness(0);
+        Debug.WriteLine($"[NavigationView] UpdateContainerTitleHeight enableCustomTitleBar={window.EnableCustomTitleBar} margin={margin}");
 
         _container.CornerRadius = new CornerRadius(8);
-        
         _container.Margin = margin;
     }
     private void OnBoundsChanged(Rect rect)
     {
+        // Ignore zero-size bounds — this fires during initial layout before the window is rendered.
+        // Acting on it would corrupt the saved expanded state of all items.
+        if (rect.Width <= 0)
+        {
+            Debug.WriteLine($"[NavigationView] OnBoundsChanged width={rect.Width:F0} → ignored (zero width, initial layout)");
+            return;
+        }
+
         if (DynamicDisplayMode)
         {
             bool isLittle = rect.Width <= LittleWidth;
@@ -517,30 +535,30 @@ private void OnBoundsChanged(Rect rect)
 
             if (!isLittle && !isVeryLittle)
             {
+                Debug.WriteLine($"[NavigationView] OnBoundsChanged width={rect.Width:F0} → CompactInline IsOpen stays");
                 UpdatePseudoClasses(false);
                 DisplayMode = SplitViewDisplayMode.CompactInline;
             }
             else if (isLittle && !isVeryLittle)
             {
+                Debug.WriteLine($"[NavigationView] OnBoundsChanged width={rect.Width:F0} → CompactOverlay IsOpen=false");
                 UpdatePseudoClasses(false);
                 DisplayMode = SplitViewDisplayMode.CompactOverlay;
                 IsOpen = false;
-                foreach (NavigationViewItem navigationViewItem in this.GetLogicalDescendants()
-                             .OfType<NavigationViewItem>()) navigationViewItem.IsExpanded = false;
             }
             else if (isLittle && isVeryLittle)
             {
+                Debug.WriteLine($"[NavigationView] OnBoundsChanged width={rect.Width:F0} → Overlay IsOpen=false");
                 UpdatePseudoClasses(true);
                 DisplayMode = SplitViewDisplayMode.Overlay;
                 IsOpen = false;
-                foreach (NavigationViewItem navigationViewItem in this.GetLogicalDescendants()
-                             .OfType<NavigationViewItem>()) navigationViewItem.IsExpanded = false;
             }
         }
     }
 
     private void SelectSingleItemCore(object? item, bool runAnimation = true)
     {
+        Debug.WriteLine($"[NavigationView] SelectSingleItemCore item={(item as NavigationViewItem)?.Header} tag={(item as NavigationViewItem)?.Tag}");
         if (SelectedItem != item && TransitionAnimation is not null && _contentPresenter is not null && runAnimation)
         {
             _cancellationTokenSource?.Cancel();
@@ -563,6 +581,7 @@ private void SelectSingleItemCore(object? item, bool runAnimation = true)
 
     private void UpdatePseudoClasses(bool isCompact)
     {
+        Debug.WriteLine($"[NavigationView] UpdatePseudoClasses isCompact={isCompact}");
         switch (isCompact)
         {
             case true:
@@ -577,16 +596,60 @@ private void UpdatePseudoClasses(bool isCompact)
     private void UpdateTitleAndSelectedContent()
     {
         if (SelectedItem is not NavigationViewItem item) return;
-            
+        Debug.WriteLine($"[NavigationView] UpdateTitleAndSelectedContent selectedItem header={item.Header} hasContent={item.Content is not null}");
         if (item.Content is not null)
             SelectedContent = item.Content;
     }
 
     private void OnSelectedItemChanged()
     {
+        Debug.WriteLine($"[NavigationView] OnSelectedItemChanged → SelectedItem={(SelectedItem as NavigationViewItem)?.Header}");
         UpdateTitleAndSelectedContent();
     }
 
+    /// <summary>
+    /// Called when the pane IsOpen state changes.
+    /// Saves IsExpanded state of all group items when collapsing to compact mode,
+    /// and restores it when expanding back to full mode.
+    /// </summary>
+    private void OnIsOpenChanged(AvaloniaPropertyChangedEventArgs e)
+    {
+        bool isNowOpen = (bool)(e.NewValue ?? false);
+        Debug.WriteLine($"[NavigationView] OnIsOpenChanged isNowOpen={isNowOpen}");
+
+        // Only group items (items that have NavigationViewItem children) participate in expand/collapse
+        var groupItems = this.GetLogicalDescendants()
+            .OfType<NavigationViewItem>()
+            .Where(item => item.Items.OfType<NavigationViewItem>().Any())
+            .ToList();
+
+        if (!isNowOpen)
+        {
+            // Pane collapsing → save IsExpanded for each group item, then collapse it
+            _expandedStates.Clear();
+            foreach (var item in groupItems)
+            {
+                _expandedStates[item] = item.IsExpanded;
+                Debug.WriteLine($"[NavigationView] OnIsOpenChanged saving header={item.Header} IsExpanded={item.IsExpanded}");
+                if (item.IsExpanded)
+                    item.IsExpanded = false;
+            }
+        }
+        else
+        {
+            // Pane opening → restore saved IsExpanded for each group item
+            foreach (var item in groupItems)
+            {
+                if (_expandedStates.TryGetValue(item, out bool wasExpanded))
+                {
+                    Debug.WriteLine($"[NavigationView] OnIsOpenChanged restoring header={item.Header} wasExpanded={wasExpanded}");
+                    item.IsExpanded = wasExpanded;
+                }
+            }
+            _expandedStates.Clear();
+        }
+    }
+
     /// <summary>
     /// Closes all open submenu popups in the navigation view.
     /// Called when a selection is made to ensure popups are dismissed.
@@ -596,7 +659,10 @@ private void CloseAllSubMenuPopups()
         foreach (var item in this.GetLogicalDescendants().OfType<NavigationViewItem>())
         {
             if (item.IsSubMenuOpen)
+            {
+                Debug.WriteLine($"[NavigationView] CloseAllSubMenuPopups closing popup on header={item.Header}");
                 item.IsSubMenuOpen = false;
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/src/PleasantUI/Controls/NavigationView/NavigationViewItem.cs b/src/PleasantUI/Controls/NavigationView/NavigationViewItem.cs
index 19dfbcaa..e8c089cd 100644
--- a/src/PleasantUI/Controls/NavigationView/NavigationViewItem.cs
+++ b/src/PleasantUI/Controls/NavigationView/NavigationViewItem.cs
@@ -1,6 +1,8 @@
-using Avalonia;
+using System.Diagnostics;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
+using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
@@ -28,6 +30,8 @@ public class NavigationViewItem : TreeViewItem
     private bool _isSubMenuOpen;
 
     private Popup? _popup;
+    private SmoothScrollViewer? _popupScrollViewer;
+    private NavigationViewSubMenuControl? _subMenuControl;
     
     /// <summary>
     /// Defines the <see cref="Content" /> property.
@@ -78,7 +82,10 @@ public class NavigationViewItem : TreeViewItem
     /// Defines the <see cref="NavigationViewDistance" /> property.
     /// </summary>
     public static readonly DirectProperty<NavigationViewItem, int> NavigationViewDistanceProperty =
-        AvaloniaProperty.RegisterDirect<NavigationViewItem, int>(nameof(NavigationViewDistance), o => o.Level);
+        AvaloniaProperty.RegisterDirect<NavigationViewItem, int>(
+            nameof(NavigationViewDistance),
+            o => o.NavigationViewDistance,
+            (o, v) => o.NavigationViewDistance = v);
 
     /// <summary>
     /// Defines the <see cref="CompactPaneLength" /> property.
@@ -109,6 +116,13 @@ public class NavigationViewItem : TreeViewItem
             o => o.IsSubMenuOpen,
             (o, v) => o.IsSubMenuOpen = v);
 
+    /// <summary>
+    /// Defines the <see cref="NavigationView" /> property.
+    /// Reference to the parent NavigationView for popup submenu items that aren't in the logical tree.
+    /// </summary>
+    public static readonly StyledProperty<NavigationView?> NavigationViewProperty =
+        AvaloniaProperty.Register<NavigationViewItem, NavigationView?>(nameof(NavigationView));
+
     /// <summary>
     /// Defines the routed event for when the <see cref="NavigationViewItem" /> is opened.
     /// </summary>
@@ -259,6 +273,16 @@ public bool IsSubMenuOpen
         set => SetAndRaise(IsSubMenuOpenProperty, ref _isSubMenuOpen, value);
     }
 
+    /// <summary>
+    /// Gets or sets the parent NavigationView.
+    /// Used by popup submenu items to navigate when not in the logical tree.
+    /// </summary>
+    public NavigationView? NavigationView
+    {
+        get => GetValue(NavigationViewProperty);
+        set => SetValue(NavigationViewProperty, value);
+    }
+
     /// <summary>
     /// Occurs when the Opened event is raised.
     /// </summary>
@@ -307,6 +331,7 @@ static NavigationViewItem()
             else
                 navigationViewItem.OnDeselected(navigationViewItem, e);
         });
+        IsSubMenuOpenProperty.Changed.Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs<bool>>(OnIsSubMenuOpenChanged));
         IsOpenProperty.Changed.Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs<bool>>(OnIsOpenChanged));
         OpenPaneLengthProperty.Changed.Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs<double>>(OnPaneSizesChanged));
         CompactPaneLengthProperty.Changed.Subscribe(new AnonymousObserver<AvaloniaPropertyChangedEventArgs<double>>(OnPaneSizesChanged));
@@ -330,6 +355,7 @@ public NavigationViewItem()
     /// <param name="e">The event arguments.</param>
     protected virtual void OnDeselected(object sender, AvaloniaPropertyChangedEventArgs e)
     {
+        Debug.WriteLine($"[NavItem] OnDeselected header={Header} tag={Tag}");
     }
 
     /// <summary>
@@ -339,11 +365,15 @@ protected virtual void OnDeselected(object sender, AvaloniaPropertyChangedEventA
     /// <param name="e">The event arguments.</param>
     protected virtual void OnSelected(object sender, AvaloniaPropertyChangedEventArgs e)
     {
+        Debug.WriteLine($"[NavItem] OnSelected header={Header} tag={Tag} parentDisplayMode={(Parent as NavigationView)?.DisplayMode}");
         if (Parent is NavigationView
             {
                 DisplayMode: SplitViewDisplayMode.CompactOverlay or SplitViewDisplayMode.Overlay
             } navigationView)
+        {
+            Debug.WriteLine($"[NavItem] OnSelected closing pane (CompactOverlay/Overlay) header={Header}");
             navigationView.IsOpen = false;
+        }
     }
 
     /// <summary>
@@ -353,6 +383,7 @@ protected virtual void OnSelected(object sender, AvaloniaPropertyChangedEventArg
     /// <param name="e">The event arguments.</param>
     protected virtual void OnOpened(object sender, RoutedEventArgs e)
     {
+        Debug.WriteLine($"[NavItem] OnOpened header={Header} tag={Tag} IsExpanded={IsExpanded}");
         UpdatePseudoClasses();
     }
 
@@ -363,11 +394,15 @@ protected virtual void OnOpened(object sender, RoutedEventArgs e)
     /// <param name="e">The event arguments.</param>
     protected virtual void OnClosed(object sender, RoutedEventArgs e)
     {
+        Debug.WriteLine($"[NavItem] OnClosed header={Header} tag={Tag} IsExpanded={IsExpanded} SelectOnClose={SelectOnClose}");
         IsExpanded = false;
         UpdatePseudoClasses();
 
         if (SelectOnClose)
+        {
+            Debug.WriteLine($"[NavItem] OnClosed SelectOnClose=true, selecting parent NavigationView item header={Header}");
             this.GetParentTOfLogical<NavigationView>()?.SelectSingleItem(this);
+        }
     }
     
     /// <inheritdoc />
@@ -376,6 +411,7 @@ protected virtual void OnClosed(object sender, RoutedEventArgs e)
     /// <inheritdoc />
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
+        Debug.WriteLine($"[NavItem] OnApplyTemplate header={Header} tag={Tag}");
         base.OnApplyTemplate(e);
 
         if (_popup is not null)
@@ -384,6 +420,15 @@ protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
         }
 
         _popup = e.NameScope.Find<Popup>("PART_Popup");
+        _popupScrollViewer = e.NameScope.Find<SmoothScrollViewer>("PART_PopupScrollViewer");
+        _subMenuControl = e.NameScope.Find<NavigationViewSubMenuControl>("PART_SubMenuControl");
+
+        Debug.WriteLine($"[NavItem] OnApplyTemplate parts found: popup={_popup is not null} scrollViewer={_popupScrollViewer is not null} subMenuControl={_subMenuControl is not null}");
+
+        if (_subMenuControl is not null)
+        {
+            _subMenuControl.NavigationViewItem = this;
+        }
 
         if (_popup is not null)
         {
@@ -398,6 +443,7 @@ protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e
     {
         base.OnAttachedToLogicalTree(e);
         NavigationViewDistance = LogicalExtensions.CalculateDistanceFromLogicalParent<NavigationView>(this) - 1;
+        Debug.WriteLine($"[NavItem] OnAttachedToLogicalTree header={Header} tag={Tag} distance={NavigationViewDistance} parent={Parent?.GetType().Name}");
     }
 
     /// <inheritdoc />
@@ -407,6 +453,7 @@ protected override void OnPointerPressed(PointerPressedEventArgs e)
 
         if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
         {
+            Debug.WriteLine($"[NavItem] OnPointerPressed header={Header} tag={Tag} clickMode={ClickMode}");
             e.Handled = true;
 
             if (ClickMode == ClickMode.Press)
@@ -425,20 +472,29 @@ protected override void OnPointerReleased(PointerReleasedEventArgs e)
 
         if (ClickMode == ClickMode.Release &&
             this.GetVisualsAt(e.GetPosition(this)).Any(c => this == c || this.IsVisualAncestorOf(c)))
+        {
+            Debug.WriteLine($"[NavItem] OnPointerReleased triggering Select header={Header} tag={Tag}");
             Select();
+        }
     }
 
     private static void OnPaneSizesChanged(AvaloniaPropertyChangedEventArgs<double> e)
     {
         if (e.Sender is NavigationViewItem navigationViewItem)
+        {
+            var prev = navigationViewItem.ExternalLength;
             navigationViewItem.ExternalLength =
                 navigationViewItem.OpenPaneLength - navigationViewItem.CompactPaneLength;
+            Debug.WriteLine($"[NavItem] OnPaneSizesChanged header={navigationViewItem.Header} openPane={navigationViewItem.OpenPaneLength} compactPane={navigationViewItem.CompactPaneLength} externalLength={prev}→{navigationViewItem.ExternalLength}");
+        }
     }
 
     private static void OnIsOpenChanged(AvaloniaPropertyChangedEventArgs e)
     {
         if (e.Sender is not NavigationViewItem sender) return;
 
+        Debug.WriteLine($"[NavItem] OnIsOpenChanged header={sender.Header} tag={sender.Tag} IsOpen={sender.IsOpen} IsExpanded={sender.IsExpanded}");
+
         if (sender is
             {
                 IsSelected: true,
@@ -446,51 +502,128 @@ private static void OnIsOpenChanged(AvaloniaPropertyChangedEventArgs e)
                 {
                     Parent: NavigationView navigationView, SelectOnClose: true
                 } navigationViewItem
-            }) navigationView.SelectSingleItem(navigationViewItem);
+            })
+        {
+            Debug.WriteLine($"[NavItem] OnIsOpenChanged selected child → SelectSingleItem on parent header={navigationViewItem.Header}");
+            navigationView.SelectSingleItem(navigationViewItem);
+        }
 
         switch (sender.IsOpen)
         {
             case true:
+                Debug.WriteLine($"[NavItem] OnIsOpenChanged IsOpen=true → closing popup header={sender.Header}");
                 sender.RaiseEvent(new RoutedEventArgs(OpenedEvent));
-                // Close popup when pane opens
                 sender.IsSubMenuOpen = false;
                 break;
             case false:
-                sender.IsExpanded = false;
+                Debug.WriteLine($"[NavItem] OnIsOpenChanged IsOpen=false → collapsing header={sender.Header}");
                 sender.RaiseEvent(new RoutedEventArgs(ClosedEvent));
                 break;
         }
     }
 
-    private void OnPopupClosed(object? sender, EventArgs e)
+    private static void OnIsSubMenuOpenChanged(AvaloniaPropertyChangedEventArgs<bool> e)
     {
-        IsSubMenuOpen = false;
-    }
+        if (e.Sender is not NavigationViewItem item) return;
 
-    private void UpdatePseudoClasses()
-    {
-        if (IsOpen)
+        Debug.WriteLine($"[NavItem] OnIsSubMenuOpenChanged header={item.Header} tag={item.Tag} IsSubMenuOpen={e.NewValue.GetValueOrDefault()}");
+
+        if (e.NewValue.GetValueOrDefault())
         {
-            PseudoClasses.Remove(":closed");
-            PseudoClasses.Add(":opened");
+            Debug.WriteLine($"[NavItem] OnIsSubMenuOpenChanged opening popup → AddPopupItemsPresenter header={item.Header}");
+            item.AddPopupItemsPresenter();
         }
         else
         {
-            PseudoClasses.Remove(":opened");
-            PseudoClasses.Add(":closed");
+            Debug.WriteLine($"[NavItem] OnIsSubMenuOpenChanged closing popup → RemovePopupItemsPresenter header={item.Header}");
+            item.RemovePopupItemsPresenter();
         }
     }
 
-    private void Select()
+    private void OnPopupClosed(object? sender, EventArgs e)
+    {
+        Debug.WriteLine($"[NavItem] OnPopupClosed header={Header} tag={Tag} → setting IsSubMenuOpen=false");
+        IsSubMenuOpen = false;
+    }
+
+    private void AddPopupItemsPresenter()
+    {
+        Debug.WriteLine($"[NavItem] AddPopupItemsPresenter header={Header} subMenuControl={_subMenuControl is not null} scrollViewer={_popupScrollViewer is not null} childCount={LogicalChildren.Count}");
+        if (_subMenuControl is null || _popupScrollViewer is null) return;
+
+        _subMenuControl.ItemsSource = LogicalChildren;
+
+        if (!ReferenceEquals(_popupScrollViewer.Content, _subMenuControl))
+            _popupScrollViewer.Content = _subMenuControl;
+
+        Debug.WriteLine($"[NavItem] AddPopupItemsPresenter done — itemsSource set childCount={LogicalChildren.Count}");
+    }
+    
+
+    private void RemovePopupItemsPresenter()
+    {
+        Debug.WriteLine($"[NavItem] RemovePopupItemsPresenter header={Header} subMenuControl={_subMenuControl is not null}");
+        if (_subMenuControl is null) return;
+
+        if (_popupScrollViewer?.Content == _subMenuControl)
+            _popupScrollViewer.Content = null;
+
+        _subMenuControl.ItemsSource = null;
+        Debug.WriteLine($"[NavItem] RemovePopupItemsPresenter done header={Header}");
+    }
+
+private void UpdatePseudoClasses()
+{
+    if (IsOpen)
     {
-        // When pane is closed (compact mode) and item has children, toggle the popup submenu
-        if (!IsOpen && ItemCount > 0)
+        PseudoClasses.Remove(":closed");
+        PseudoClasses.Add(":opened");
+    }
+    else
+    {
+        PseudoClasses.Remove(":opened");
+        PseudoClasses.Add(":closed");
+    }
+    Debug.WriteLine($"[NavItem] UpdatePseudoClasses header={Header} IsOpen={IsOpen} pseudoClasses=[{string.Join(",", PseudoClasses)}]");
+}
+
+private void Select()
+{
+    var navigationView = this.GetParentTOfLogical<NavigationView>() ?? NavigationView;
+    var isPaneOpen = navigationView?.IsOpen ?? IsOpen;
+    var hasChildren = this.LogicalChildren.OfType<NavigationViewItem>().Any();
+    bool isPopupClone = navigationView is not null && this.GetParentTOfLogical<NavigationView>() is null;
+
+    Debug.WriteLine($"[NavItem] Select header={Header} tag={Tag} isPaneOpen={isPaneOpen} hasChildren={hasChildren} isPopupClone={isPopupClone} IsSelected={IsSelected}");
+
+    if (!isPaneOpen && hasChildren)
+    {
+        Debug.WriteLine($"[NavItem] Select compact+hasChildren → toggling IsSubMenuOpen={!IsSubMenuOpen} header={Header}");
+        IsSubMenuOpen = !IsSubMenuOpen;
+        return;
+    }
+
+    if (isPopupClone && navigationView is not null && Tag is not null)
+    {
+        var original = navigationView.GetLogicalDescendants()
+            .OfType<NavigationViewItem>()
+            .FirstOrDefault(x => Equals(x.Tag, Tag));
+        Debug.WriteLine($"[NavItem] Select popup clone → found original={original?.Header} tag={Tag}");
+        if (original is not null)
         {
-            IsSubMenuOpen = !IsSubMenuOpen;
+            navigationView.SelectSingleItem(original);
             return;
         }
+    }
 
-        if (!IsSelected)
-            this.GetParentTOfLogical<NavigationView>()?.SelectSingleItem(this);
+    if (!IsSelected)
+    {
+        Debug.WriteLine($"[NavItem] Select → calling SelectSingleItem on NavigationView header={Header} tag={Tag}");
+        navigationView?.SelectSingleItem(this);
+    }
+    else
+    {
+        Debug.WriteLine($"[NavItem] Select → already selected, skipping header={Header}");
     }
+}
 }
\ No newline at end of file
diff --git a/src/PleasantUI/Controls/NavigationView/NavigationViewSubMenuControl.cs b/src/PleasantUI/Controls/NavigationView/NavigationViewSubMenuControl.cs
new file mode 100644
index 00000000..e9e6e9c7
--- /dev/null
+++ b/src/PleasantUI/Controls/NavigationView/NavigationViewSubMenuControl.cs
@@ -0,0 +1,167 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.Presenters;
+using Avalonia.Controls.Primitives;
+using Avalonia.Layout;
+using Avalonia.LogicalTree;
+using PleasantUI.Core.Extensions;
+
+namespace PleasantUI.Controls;
+
+/// <summary>
+/// A control that hosts submenu items for NavigationViewItem's popup.
+/// This is a separate control instance that creates its own NavigationViewItem containers,
+/// avoiding visual parent conflicts with the inline ItemsPresenter.
+/// </summary>
+public class NavigationViewSubMenuControl : ItemsControl
+{
+    private ItemsPresenter? _itemsPresenter;
+
+    /// <summary>
+    /// Defines the <see cref="NavigationViewItem" /> property.
+    /// </summary>
+    public static readonly StyledProperty<NavigationViewItem?> NavigationViewItemProperty =
+        AvaloniaProperty.Register<NavigationViewSubMenuControl, NavigationViewItem?>(nameof(NavigationViewItem));
+
+    /// <summary>
+    /// Gets or sets the parent NavigationViewItem that owns this submenu.
+    /// </summary>
+    public NavigationViewItem? NavigationViewItem
+    {
+        get => GetValue(NavigationViewItemProperty);
+        set => SetValue(NavigationViewItemProperty, value);
+    }
+
+    static NavigationViewSubMenuControl()
+    {
+        // No ItemTemplate - we create NavigationViewItem containers directly
+        ItemTemplateProperty.OverrideDefaultValue<NavigationViewSubMenuControl>(null);
+    }
+
+    public NavigationViewSubMenuControl()
+    {
+        Classes.Add("navigationViewSubMenu");
+    }
+
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+    {
+        base.OnApplyTemplate(e);
+        _itemsPresenter = e.NameScope.Find<ItemsPresenter>("PART_ItemsPresenter");
+    }
+
+    /// <inheritdoc />
+    protected override Control CreateContainerForItemOverride(object? item, int index, object? recycleKey)
+    {
+        // Always create a fresh NavigationViewItem container
+        var container = new NavigationViewItem();
+        return container;
+    }
+
+    /// <inheritdoc />
+    protected override bool NeedsContainerOverride(object? item, int index, out object? recycleKey)
+    {
+        // Always create a new container, never reuse the item directly
+        recycleKey = null;
+        return true;
+    }
+
+    /// <inheritdoc />
+    protected override void PrepareContainerForItemOverride(Control element, object? item, int index)
+    {
+        base.PrepareContainerForItemOverride(element, item, index);
+
+        if (element is NavigationViewItem navItem && item is not null)
+        {
+            // The item is either:
+            // 1. A NavigationViewItem (from LogicalChildren) - we need to copy its properties
+            // 2. A data object - we need to set it as the container's data context
+            
+            if (item is NavigationViewItem sourceItem)
+            {
+                // Copy all relevant properties from the source NavigationViewItem
+                navItem.Header = sourceItem.Header;
+                navItem.HeaderTemplate = sourceItem.HeaderTemplate;
+                navItem.Icon = sourceItem.Icon;
+                navItem.Content = sourceItem.Content;
+                navItem.Title = sourceItem.Title;
+                navItem.Tag = sourceItem.Tag;
+                navItem.IsSelected = sourceItem.IsSelected;
+                navItem.SelectOnClose = sourceItem.SelectOnClose;
+                navItem.ClickMode = sourceItem.ClickMode;
+                
+                // Clone the children recursively - create NEW NavigationViewItem instances
+                // Do NOT add the original children as they already have visual parents
+                foreach (var child in sourceItem.Items.OfType<NavigationViewItem>())
+                {
+                    var clonedChild = CloneNavigationViewItem(child);
+                    navItem.Items.Add(clonedChild);
+                }
+            }
+            else
+            {
+                // It's a data object, set it as the DataContext
+                navItem.DataContext = item;
+                navItem.Header = item;
+            }
+
+            // Apply styling from parent NavigationViewItem and propagate NavigationView reference
+            var parent = NavigationViewItem;
+            if (parent is not null)
+            {
+                navItem.CompactPaneLength = parent.CompactPaneLength;
+                navItem.OpenPaneLength = parent.OpenPaneLength;
+                navItem.IsOpen = true; // Submenu items always show as open in popup
+                // Propagate the NavigationView reference so popup items can trigger navigation
+                navItem.NavigationView = parent.NavigationView ?? parent.GetParentTOfLogical<NavigationView>();
+            }
+        }
+    }
+
+    /// <inheritdoc />
+    protected override void ClearContainerForItemOverride(Control element)
+    {
+        base.ClearContainerForItemOverride(element);
+
+        if (element is NavigationViewItem navItem)
+        {
+            // Clear properties to prepare for recycling
+            navItem.Header = null;
+            navItem.Icon = null;
+            navItem.Content = null;
+            navItem.DataContext = null;
+            
+            // Reset distance
+            navItem.SetValue(NavigationViewItem.NavigationViewDistanceProperty, 0);
+        }
+    }
+
+    /// <summary>
+    /// Recursively clones a NavigationViewItem and all its children.
+    /// Creates completely new instances to avoid visual parent conflicts.
+    /// </summary>
+    private static NavigationViewItem CloneNavigationViewItem(NavigationViewItem source)
+    {
+        var clone = new NavigationViewItem
+        {
+            Header = source.Header,
+            HeaderTemplate = source.HeaderTemplate,
+            Icon = source.Icon,
+            Content = source.Content,
+            Title = source.Title,
+            Tag = source.Tag,
+            IsSelected = source.IsSelected,
+            SelectOnClose = source.SelectOnClose,
+            ClickMode = source.ClickMode,
+            IsOpen = true // Submenu items always show as open in popup
+        };
+
+        // Recursively clone all children using public Items property
+        foreach (var child in source.Items.OfType<NavigationViewItem>())
+        {
+            var clonedChild = CloneNavigationViewItem(child);
+            clone.Items.Add(clonedChild);
+        }
+
+        return clone;
+    }
+}
diff --git a/src/PleasantUI/Styling/ControlThemes/PleasantControls/NavigationViewItem.axaml b/src/PleasantUI/Styling/ControlThemes/PleasantControls/NavigationViewItem.axaml
index feb3aa52..e87b54c5 100644
--- a/src/PleasantUI/Styling/ControlThemes/PleasantControls/NavigationViewItem.axaml
+++ b/src/PleasantUI/Styling/ControlThemes/PleasantControls/NavigationViewItem.axaml
@@ -119,7 +119,7 @@
                                     </Grid>
                                 </RippleEffect>
                             </Border>
-                            <Border Grid.Row="1" Name="PART_BottomBorder">
+                            <Border Grid.Row="1" Name="PART_BottomBorder" ClipToBounds="True">
                                 <ItemsPresenter Name="PART_ItemsPresenter"
                                                 ItemsPanel="{TemplateBinding ItemsPanel}" />
                             </Border>
@@ -161,12 +161,11 @@
                                     MinWidth="160"
                                     MinHeight="32"
                                     CornerRadius="{StaticResource ControlCornerRadius}">
-                                <SmoothScrollViewer HorizontalScrollBarVisibility="Disabled"
+                                <SmoothScrollViewer Name="PART_PopupScrollViewer"
+                                                    HorizontalScrollBarVisibility="Disabled"
                                                     VerticalScrollBarVisibility="Auto"
                                                     MaxHeight="400">
-                                    <ItemsPresenter Name="PART_PopupItemsPresenter"
-                                                    ItemsPanel="{TemplateBinding ItemsPanel}"
-                                                    Margin="0 4 0 4" />
+                                    <NavigationViewSubMenuControl Name="PART_SubMenuControl" />
                                 </SmoothScrollViewer>
                             </Border>
                         </ShadowBorder>
@@ -319,6 +318,13 @@
         <Style Selector="^[IsExpanded=False] /template/ :is(Control)#PART_BottomBorder">
             <Setter Property="Height" Value="0" />
         </Style>
+
+        <!-- When pane is closed (compact mode), always collapse inline children regardless of IsExpanded.
+             This selector has higher specificity than [IsExpanded=False] alone, so it wins. -->
+        <Style Selector="^[IsOpen=False] /template/ :is(Control)#PART_BottomBorder">
+            <Setter Property="Height" Value="0" />
+            <Setter Property="IsVisible" Value="False" />
+        </Style>
         
         <Style Selector="^:selected /template/ ContentPresenter#PART_ContentPresenter">
             <Setter Property="Transitions">
@@ -375,4 +381,15 @@
             <Setter Property="Background" Value="{DynamicResource ControlFillColor2}" />
         </Style>
     </ControlTheme>
+
+    <!-- ControlTheme for NavigationViewSubMenuControl -->
+    <ControlTheme x:Key="{x:Type NavigationViewSubMenuControl}" TargetType="NavigationViewSubMenuControl">
+        <Setter Property="Margin" Value="0 4 0 4" />
+        <Setter Property="Template">
+            <ControlTemplate>
+                <ItemsPresenter Name="PART_ItemsPresenter" 
+                                ItemsPanel="{TemplateBinding ItemsPanel}" />
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
 </ResourceDictionary>
\ No newline at end of file