Loosing connection

Since 5.0.1 and still with 5.0.3 openHAB looses connection to homematic with these messages in the log:

[WARN ] [core.thing.internal.ThingManagerImpl] - Could not normalize configuration for 'homematic:HM-Sec-SCo:3014F711A061A7DBE9975EA1:MEQ0717962' because the thing type was not found in registry.
[WARN ] [core.thing.internal.ThingManagerImpl] - Channel types or config descriptions for thing 'homematic:HM-Sec-MDIR-3:3014F711A061A7DBE9975EA1:OEQ1125928' are missing in the respective registry for more than 120s. In case it does not happen immediately after an upgrade, it should be fixed in the binding.

These lines fill up the log for every homematic thing configured. I first thought cuxd might have crashed but restarting did not help. So I tried restarting the homematic binding which did not help either. I really have to restart openHAB completely in order to have access to my homematic devices again.

openHAB complains about incomplete configuration.
This won’t disappear without updating the configuration, so take a closer look at it.

How did you configure the thing?
What does the configuration look like? (as code)

Complaining about incomplete configuration does not make any sense. My homematic configuration has not changed since openHAB 4.x. openHAB was running for hours before loosing connection and flooding the log with these error messages.

The only thing that changed was a time table for a homematic heating group. The log snippet relates to a window contact which is not part of the group and a motion sensor. The whole log file seems to include all of my homematic things.

If it was a configuration issue openHAB should have started with these messages after initializing things. I guess it is an issue of running longterm and things getting messed up internally. I did not see this kind of warnings before 5.0.3 but had issues with the communication between openHAB and homematic before. Sometimes these issues could be resolved by disabling and enabling the CCU thing. Sometimes I had to fully restart openHAB.

After updating to 5.1, the item values are no longer being updated.

The thing is online, but it seems that communication is no longer taking place.

I use the Homematic binding with Homegear (where the CUL gateway and all devices are online).