Disconnect all of the HDMI cables from the TV and power down the TV and BEAM. Keep the TV powered down for at least two minutes. Now, power up the TV and BEAM, then connect BEAM to the TV’s HDMI-ARC port. Don’t connect anything else to the TV at this point. This will force the units to renegotiate their interactions with each other.

Work with the system for a while. If the system behaves, then start adding other devices, one at a time, and work with the system after each addition. If you discover a bad actor, you can isolate it with a CEC blocker.

CEC (Consumer Electronic Control) is a communication scheme using the HDMI cables to share operational information. The ideal is when a cable box announces that it has powered-up and the TV and A/V receiver or BEAM will respond by powering-up and selecting the correct inputs. Unfortunately, industry standards are lax and there can be glitches. One of my favorite glitches is the middle of the night cable box update ending with powering-up the cable box. CEC assumes that you really want to watch TV and starts everything … . I make a point of muting the audio when I stop using the system. When CEC works, it’s great because all of the individual remotes can change channels and adjust Volume -- and none of this requires any explicit user setup -- it just works. When CEC does not work, it’s a big pain and a Blocker is the only practical solution, but it might also block some remote control conveniences.