Matter - I tried it and need help

I have upgraded an Eve energy plug to Matter (via their beta program). I managed to add it to Google Home (Nest hub 2 as a border router). Then I shared it with HA and … it even worked! Now I have the plug as a device in HA. My setup: HA 2023.2.2, matter running as add-on, thread is done via the Skyconnect USB stick with the Silabs multi-protocol.
The problem is: I can switch on the plug with HA but then it immediately bounces the state back to Off. The plug stays on. So I can’t switch it off with HA anymore. The same works without issues with Google home.
Any idea how to debug that?

I have the exact same issue.