I have installed fresh openHAB 4.0.1 as recommended by mstormi.
Out of a total of 43 AVM devices, only 22 are recognised, the rest are in the unknown state.
Version 3.4.3 recognises all AVM devices.
The other add-ons (e.g. Homematic, Gardena…) work in both versions.
Does anyone have a tip for me?