Beam: Keeps switching back to ARC from Bluetooth - how to stop?

I just purchased a new Samsung TV today and a Sonos beam+sub and now have this issue when connecting my Bose Bluetooth headset. The HDMI-CEC workaround is not good/nice, so I really hope that Sonos can fix this issue somehow.

It’s a ‘feature’ of the HDMI-CEC spec. Connect your Beam via optical, or your headphones, and there won’t be that conflict. 

In very simple setups HDMI-CEC can work well, however, in more complicated setups it is a hazard. You can get into a situation where the order of commands is important. For example if one turns OFF the TV, then turns OFF the Blue-ray player, the TV is likely to turn ON again and switch to the cable box. This can create interesting dramas if one partner is sleeping and the other had been watching a disc. This becomes worse if the viewing partner falls asleep without properly shutting down the system. Eventually, most Blu-ray players will automatically turn OFF after a disc ends and there are no further commands. Another drama unfolds if the cable company updates their firmware in the middle of the night because the TV might turn ON after the update is complete.

Overall, Airgetlam’s solution of using an optical connection for Bluetooth is the most practical, but I can imagine misadventures here too. Eventually there will be cost effective add-on control systems that can manage CEC, but I wouldn’t hold my breath waiting for these.

Realise this thread is a bit old but came across it when I was searching for an answer to the same issue I am having and can confirm that the brand new Sonos Arc also has the exact same problem. Using Sonos Arc with LG C9 connected via eARC with CEC enabled and am now not able to use any other audio outputs. After selecting any of them, it jumps back to ARC after a couple of seconds.
Hope its a bug that gets resolved as currently the implementation of CEC on this flagship Sonos soundbar is quite disappointing.

I've had Beam and sub 3.1 combo for 2 years now hooked up to a LG E8 and have to switch HDMI CEC  off to use bluetooth with my  headphones. I see it as a CEC issue not a Sonos one. I also have CEC issues when activating CEC and other items like ATV4K and a Foxtel cable box I need to turn it off for the Apple box. 

I think the issue is due to Sonos being a music player and media streamer and not just a dumb soundbar.  

Same behavior. I can't use any other audio options other than the internal speakers. With Bluetooth I get a second of sound, then the ARC takes back the output. On my LG OLED I can't even turn off hdmi-cec as it turns it back on when I switch to the sound bar. 

All I want is to be able to use Bluetooth headphones at night.…

Sigh....

thank you!!  Found this through a Google search. I have an LG OLED B8 with the Beam and have the same problem! This is unfortunately a temporary and annoying work around.  My Bose 700 bluetooth headphones cost more than the Beam, can't Sonos step up to allow us to switch between them quickly?? I use them at night so i don't bother the wifey while enjoying some late night TV in our condo.

Can't Sonos fIx such a simple issue? I'm sure thousands of others have this issue.

It is unfortunate to see this hasn’t been corrected even in new products. I purchased a Sonos Arc to go with LG CX. Due to COVID my wife is currently working from home, in order not to disturb her, I was trying to use Bluetooth headphones, then tried wired headphones, arc keeps overriding my choice after a few seconds. May send it back, as while I can do the “fix” mentioned above, a current device shouldn’t be forcing me to turn off features of the tv just to work properly, especially since this an over a year old issue.

Edit: This isn’t an LG issue, I hooked up my older Bose sound bar and sound output selections work properly.

I’ve got the same issue. LG C8 and ARC. Will try the CEC route this evening. It’s not ideal to have to do a work around as you would think the integration between Sonos and LG would be better. 

I bought an Alexa enabled plug. I say “Alexa turn Arc off.” It powers down. The  Bluetooth sticks because the Arc power is off. Just have to turn back on in am.