LG OLED C5 + Beam Gen 2: Sound Out reverts from Bluetooth to ARC within 5s; SIMPLINK auto-re-enables

It may be better to petition the CEC consortium for an option. Having not read the agreement required between the two parties, it is possible that Sonos isn’t allowed to develop such an option.

I’m also of the opinion this would be an issue to the vast majority of users who expect CEC to ‘just work’, and to require a check for such a small corner case might be detrimental. Both to Sonos, and all CEC devices. 

The CEC protocol seems to leave room for Sonos devices to check for CEC status more than devices from other manufacturers seem to do, while also leaving room for LG to automatically turn on CEC when it is turned off. This means you probably won’t get anywhere when petitioning either Sonos or LG - both must have good reasons for their devices’ behaviour and seem free to do so within the CEC protocol.

The Sonos solution for this is the Ace headphones, that connect to the Sonos soundbar, not the TV.

Discussed at length here too...

https://en.community.sonos.com/home-theater-229129/major-problem-with-sonos-arc-ultra-sonos-doesn-t-let-switch-to-other-speakers-from-tv-menu-6932228

@Airgetlam — the CEC-consortium framing isn't quite right. Samsung soundbars and Sennheiser bars on the same LG TVs do not trigger this re-assertion. The CEC protocol allows user-overrode output to be respected; the issue is the Sonos Beam re-asserts CEC presence aggressively, causing LG webOS to re-enable SIMPLINK and re-route audio to ARC within ~5s of any manual Sound Out change.

@106rallye — "buy Sonos Ace" isn't a fix when the customer already paid for Beam + Sony WH-1000XM5 + LG OLED. Telling people their $1k+ existing gear can't work together unless they buy an additional $449 product is consumer-hostile.

I cross-referenced with the active Arc Ultra thread (topic 6932228, 36 replies / 1297 views): same SIMPLINK re-assertion bug, broader product line. Best answer there concludes "a call to LG is warranted."

Asking again for one of: (1) a "silent on CEC bus" option in the Beam app, (2) a configurable cooldown after a user manually sets Sound Out, (3) Sonos formally engaging LG engineering on this multi-gen webOS regression (BX, CX, C2, G1, G4, C5).

Filed parallel complaints with LG Email-to-President (follow-up, no response in 10 days) and Sony WH-1000XM5 support.

Which may be why I said ‘may’. In any case, you’re much more likely to get ‘official’ response from Sonos Support by calling them, and speaking to a Sonos rep directly. The vast majority of users on this public forum are not Sonos employees. Your request may be passed on in a forum summary report, at best, but doesn’t carry, IMHO, the same ‘oomph’ as a direct call would. Of course, a direct call takes more effort, and you have to get past the AI ‘bot, but might be worthwhile.

Out of curiosity, do you know if the Samsung and Sennheiser soundbars have fully implemented CEC? I don’t know offhand if Sonos is more rigorous or less, but I’ve always assumed, since they’re only a speaker manufacturer, they honed closely to the specs. Samsung could have used extended commands, since they only want you to use their own equipment across the board, but since Sennheiser doesn’t, there’s questions…unless Sennheiser (and/or Samsung) doesn’t actually use CEC. You didn’t specify which components you’re referring to, so it’s harder to look them up for review of the specs. 

Each manufacturer claims that its use of CEC is correct and the other guys are wrong. One or both companies can make a change, but the changes can cross and there is still some sort of issue that is obviously the other guy’s fault. If there are multiple devices, one of them might assume that it is in charge and will constantly attempt to play. Installing a CEC blocker can sometimes calm things down.