One eye sends signal (light)
One eye receives (off, no light).
So you will always only see light from one eye.
That is normal.
Try resetting the board back to factory settings.
Instructions from the DX users manual.
Resetting the software
If you would like to reset your software to the factory default settings, gain access to the tourney button your board, then enter the programming mode. While in programming mode, press and hold the tourney lock button.
After approximately 10 seconds, your indicator LED will flash all colours indicating a reset has been completed.