Issues with Devolo MT02792 Home Control Metering Plug - "Request_NIF"

The plug was added via PaperUI. It is online for a few days already and can be reached but continues to be in Status “Request_NIF”.
When I originally added it, the status was ok but at some point in time it changed to the above status and I can not get it back to normal it seems.
What can I do about this?