Video doorbell offline

After the latest iOS update of the app, the video ( wired ) doorbell keeps going offline.

It says: doorbell battery offline.

But when I unplug the doorbell from the wires and let it charge with the excluded charging cable, it immediately gives a battery of 100%.

After reconnecting to the wall and with the wires it works for a few hours and than it goes offline again.

I have the doorbell for 3 months now and it’s the first time I encounter this issue ( 2x in 2 days ).

Best regards.