I have a HDX 9004 with 3.1.5 with camera two not responding to the remote or web remote. In addition Admin Settings > Camera > Camrea 2 is showing up as an unknown camera.
This camera is connected with the HDCI Camera Break-Out Cable and has previously work until today.
Obvious question is if all the cables are making connection. If you swap camera 1 and camera 2 inputs what happens? If you swap the cameras at the other end of the cables what happens?
Since the detection is not happening that would point to the camera output or the DB9 cable. I would make sure that the DB9 cable has not been damaged.
Connections physically appear to be good.When hooking camrea 1 into camrea 2 input, we get no signal. When hooking camera 2 up to camrea input 1. the camrea works but without control.