I should mention that I never monitored the CPU usage through “top” on Bullseye since I didn’t experience any issues back then.
I would appreciate any input on whether others have observed similar behavior after the upgrade, and what steps I could take to identify the root cause.
Especially for openHABian, we do not recommend to do an upgrade but a complete new innstall with backup and resrore of your openHAB config.
We had a lot information in the past, where OS upgrades failed completely.