Supervisor left-hand menu opening custom dashboard instead of supervisor dashboard

I have a problem that my supervisor icon on the left side suddenly is opening one of my custom ligh dashboards instead of the supervisor page. No clue what happened. It worked for a long time as it should and now when clicking the supervisor icon my light dashboard opens. Any hint on how to fix this ? Tried supervisor repair, removed- added back in the icon in config.yaml, but no change. The supervisor log has this warning entry: [supervisor.homeassistant.websocket] Can't send WebSocket command: Can't connect to Home Assistant Core WebSocket, the API is not reachable. HomeAssistant is working fine, including updates. In case it might be relevant: I am not sure if the problem has to do with this: I migrated HA from a RPi5 to a Ugreen NAS VM. Went smooth and HA worked instantly. I have a cascaded router setup: DSL router FritzBox and cascaded a UDR that does all automation stuff, cctv, access. The nas itsself is connected to the FritzBox, HA is on a UDR VLAN, so I used a USB-ethernet adapter connected to the UDR. HA is thus still on the UDR VLAN like before. The migration worked immediately and flawlessly. I don’t know what to look into. Any pointer would be appreciated. Even Thread is working on the nas, so I would think I have no networking issues.

My first thought... That is very hard to read. TL;DR

My second thought is look at what I am using for adding entries to the left hand. Something there might help you. Remember these have my IP address and you would need to change it to yours.