Connection state is not updated when server connection is lost

[abdullahtellioglu]

Description of the bug

When server shuts down, the window.Vaadin.connectionState states the connection is still intact. It should be updated whenever server communication state changes

Expected behavior

After server restart, it should become disconnected so event consumers would be notified when the communication state changes.

Minimal reproducible example

• Run any application
• Wait until communication is established
• Stop the server
• Check window.Vaadin.connectionState

Versions

Flow: 25.2-SNAPSHOT
Vaadin: 25.1.0-rc2
Spring Boot: 4.0.4
Spring: 7.0.6
Copilot: 25.2-SNAPSHOT
Frontend Hotswap: Vite
OS: aarch64 Mac OS X 26.2
Java: JetBrains s.r.o. 21.0.6
Browser: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36
Spring Security: true
Spring Data JPA: true
Java Hotswap: Java Hotswap is enabled
IDE Plugin: 1.5.10 IntelliJ