Bose lifestyle 650 and cable box “Z Alpha”: Remote not working

I have connected the cable box “Z Alpha” the the 3rd hdmi port of the lifestyle 650. I have added the device and it is recognised. However, the control remote of this device now attemptA to communicate with Bose lifestyle (I see the front light of Bose 650 blinking when I press the button of the “z alpha” remote).

 

It creates a major problem because the cable box can only be controlled by the remote control and the remote does not seem to command the cable box anymore when connected to Bose 650. Please help.