Error: Handler & HANDLER_CONFIGURATION_PENDING

Hi
I experience after weeks of proper function, that 2 out of my 4 «MDT AMI-1612.01 switch actuators» can lo longer reached via OH3 (3.0.1). In things «Error: Handler» («HANDLER_CONFIGURATION_PENDING») is raised.
It works fine for the other 2 MDT AMI-1612.01 switch actuators.
All the 4 have the same configuration (i.e. pingInterval: 600 / readInterval: 0 / fetch: false) and are bridged via the same KNX IP gateway.
It also not related to the application version of the actuators (i.e. 1.4).

openhab.log has multiple enties with the following content: (might be the two devices)
[WARN ] [calimero.mgmt.MC 192.168.10.11:3671 ] - problem reading property (response 43 d6 00 4e 00 01): property access OI 0 PID 78 failed/forbidden
[WARN ] [calimero.mgmt.MC 192.168.10.11:3671 ] - problem reading property (response 43 d6 00 01 00 00): property access OI 0 PID 1 failed/forbidden

event.log shows
[INFO ] [ab.event.ThingStatusInfoChangedEvent] - Thing ‘knx:device:bridge:b126051b64’ changed from UNINITIALIZED (HANDLER_CONFIGURATION_PENDING) to UNINITIALIZED (HANDLER_MISSING_ERROR)

Logging seems to reflect the reality :slight_smile:
Has anybody an idea what to check or change in the config?

Thank you for you support and response on that topic.

Dodo