AVM Binding and AVM DECT 200 and some 546e

environment:

Raspberry Pi3B
Openhab 2.5.1
Fritzbox 7490 FW 7.19

With the automatic search the adapters are found several times, always via the 546e repeaters.
But in the binding the brigde (7490) was defined.
If you search for the DEC 200 you can also find them via the Fritzbox 7490 in the Inbox.

I have created the items in my own items and the addresses are correct.

This runs exactly one day.
Then the Dect 200 cannot be switched (manually, event trigger).

The whole thing has been rebuilt completely, same problem. Now you read that the Fritzbox sometimes rejects the connection? So why is the device online within OH2?
The only ones that can be addressed are the 546e repeaters because they are addressed directly over the IP.
Do you have any experience with DECT 200 and the connection to OH2?

Thanks in advance

I have been using 5 dect200, 1 dect 210 and 1 dect 310, connected with a fritzbox 7590 with fritzOS 7.19. I am using openhab 2.5.0.

I do not understand if your problem is on the openhab side or on the fritzbox side. Can you operate the switches from the fritzbox? It happened to me once that I had to re-connect my dect210 to the fritzbox, because it was not possible to operate it anymore.