DIRIGERA TBR & HA Matter Server with Aqara P2

As OTBR is lagging behind in HA I switched to use a DIRIGERA as Thread border router and removed the SkyConnect Thread dongle. DIRIGERA is not used as a controller atm. Adding Thread Matter devices to the HA Matter server works fine, via the DIRIGERA Thread network. But strangely, the Aqara P2 motion sensors that worked fine before on the HA OTBR network now somehow act up. While I can ping them via IPv6, they don’t really detect motion but do return Occupancy detected every 10min (which I think is the ping period of HA Matter server?) and clear a minute later. On these two events, a probably correct illuminance is a is also transmitted. Any ideas? An interesting part might also be the device info showing unknown type and a strange network name:

Device info
Node ID:
124
Network type:
Thread
Device type:
Unknown
Network name:
@��z�`