docker system prune does not remove reclaimable space

[dominikzalewski]

Current behaviour

root@acme:~# docker container ls -a
CONTAINER ID   IMAGE                                                       COMMAND                  CREATED      STATUS                PORTS                                                                          NAMES
39900d4aa961   registry.acme.io/core:4.47                            "catalina.sh run"        4 days ago   Up 4 days (healthy)   0.0.0.0:8080->8080/tcp, [::]:8080->8080/tcp                                    core_app.1.trzd1zc12hp6cr7avcvahwrya
21af351e5098   nginx:1.29.2                                                "/docker-entrypoint.…"   4 days ago   Up 4 days             0.0.0.0:80->80/tcp, [::]:80->80/tcp, 0.0.0.0:443->443/tcp, [::]:443->443/tcp   core_proxy.1.s3fp15dvaryq0droxsl3jok7i
27db266adca1   ghcr.io/pellepelster/solidblocks-rds-postgresql:17-v0.4.6   "/rds/bin/run.sh"        4 days ago   Up 4 days             5432/tcp                                                                       core_db.1.f6wddqmo19q77x8xaoonqxy78
root@acme:~# docker image ls
REPOSITORY                                        TAG       IMAGE ID       CREATED        SIZE
registry.acme.io/core                       <none>    40f97602d1eb   5 days ago     607MB
ghcr.io/pellepelster/solidblocks-rds-postgresql   <none>    a4d548f775a6   3 weeks ago    146MB
registry.acme.io/core                       4.29      d6bb381c8b81   5 months ago   593MB
nginx                                             <none>    657fdcd1c365   5 months ago   152MB
root@acme:~# docker system df
TYPE            TOTAL     ACTIVE    SIZE      RECLAIMABLE
Images          4         3         1.499GB   593.4MB (39%)
Containers      3         3         566.6MB   0B (0%)
Local Volumes   5         5         26.73GB   0B (0%)
Build Cache     0         0         0B        0B
root@lagerinn:~# docker system prune -f 
Total reclaimed space: 0B

Expected behaviour

Reclaimable space, ie. image

registry.acme.io/core                       4.29      d6bb381c8b81

is removed.