EufyCam 2 is Pro unable to establish secure video channel

So with a 4 camera kit, 3 cameras connect to Homebase 3 no problem and work fine, but fourth camera connects (syncs) with homebase but then can never “establish a secure video channel “. I have removed and re-added camera several times, but problem persists. Some communication between homebase and camera is occurring as I can change some settings eg Camera name, theft alarm etc, but can’t change any video settings.
Dud camera? Any ideas how to remedy?

What happens if you move the bad camera next to one of the good ones? If it works there, then it is signal or interference issues, not camera. If it doesn’t work in a location where the others work, then its probably a bad camera.