I have the same problem.
Last month I purchased the Eufy HomeBase + 2 Camera pack.
It was a breeze to setup and install the system. All have been working fine, and I am pleased with the system.
This month, I decided I needed another camera, and bought an additional one.
However, even after following the same procedures as the 1st 2 cameras, I am unable to add the new camera.
Always the same “unable to add the device” error.
I followed the troubleshooting steps above and still failed to add the camera. Figuring that the camera must be faulty, I returned it to JB Hifi for a replacement, and got a brand new camera in exchange.
However, this camera faces the same problem as well. I don’t think 2 brand new cameras can be faulty - so it must be the process, or the homebase.
Please advise how I can get this camera added and functional. Thanks!