[solved] Howto transfer config to new system (Core & venv)?

I know that there is a backup option, searched the docs/forum but couldn’t find more details on restoring if not migrating to HAOS.

I have restored the contents of that backup file to the proper location on a new similar setup, checked/corrected ownership & permissions and (re)started HA.
Even so, I keep getting a non-configured system although the yaml files are the correct ones.

Am I missing something or is there another way to get this done?

EDIT: after multiple restarts things changed and now my system is to the state from my backup…