Fibaro Walli Switches suddenly blinking dark blue

I searched the Fibaro forum for this problem with Walli switches, but did not find anything about it.
But I know a case where a user had the same problem with several Fibaro RS3. The user had even contacted Fibaro, but without a satisfying result.

These are the corresponding posts in the Homey and Fibaro forum:

So my recommendation is to contact the dealer and/or Fibaro.