I started with a fresh installation with openHAB 4.3.1. My previous server version was 4.2.0.
On the new installation the Fritzbox bridge and some smart home devices become ONLINE, while other start UNKNOWN. I restarted both Fritzbox and openHAB, but that didn’t fix the issue. The bridge has the same config.
The log only says Thing 'avmfritz:FRITZ_DECT_440:...' changed from INITIALIZING to UNKNOWN for this thing.
When setting log level to trace, I can see the following line GET response complete: <devicelist ...
It contains a full device list including the devices the are unknown. I also double checked the AIN from the log and the config.
It happens to several device types, e.g. FRITZ!DECT 440. One of them is online, others are unknown.