Sonos Arc & LG G1 with eARC: Issues using Bluetooth Headphones

this is not a tv issue!  this is 100% a sonos issue with HDMI eArc connectivity.  sonos needs to take accountability with this issue and fix the problem.  i install tvs and sonos for a living and have this problem with multiple brands of tvs with any sonos plugged into tvs with hdmi eARc/ARc.  the only work around that i have found that works is to use the optic adaptor.  you then need to ensure the sound on the soundbar is turned down to down low so you can use the bluetooth headphones with this.  obviously not an ideal work around as it doesn’t allow dolby atmos.  COME ON SONOS!!!!!!!YOU ARE BETTER THAN THIS!!!!FIX THIS PROBLEM!!!!!!!!!

No, it’s not a TV issue. Nor is it a Sonos issue. If you’re a TV installer, you should take a few minutes to familiarize yourself with the design specifications for CEC, and ask those who set up those specifications why they only permit a single sound ‘sink’ device at a time. Both the TV manufacturers and Sonos have designed their systems to that specification. 

FWIW, I have a LG CX 55” in the bedroom that will allow for SIMPLINK to be switched off and compliant with the SONOS BEAM GEN 2 and bose bt soundwear.
HOWEVER, the LG C1 65” in the living room is more proudy and refuses to give up control of the hdmi arc, and simplink will turn back on with seconds. So whatever change LG made between the CX - C1 is conflicting. Ive been in touch with LG, but tech level 1? dont seem to understand the problem and have referred me up the chain of command. Im not really sure if this is a SONOS or LG issue, but one solution that Im contemplating is buying a Nvidia Shield 2019 for the living room after using the 2019 Pro on the CX. (The cx is in my bedroom whereas the C1 is a living room thing). Im not entirely impressed with the WebOS UI anyways and I know google tv (shield) would be a better solution for both watching content, dolby atmo hdr vision upscaling etc, and the BT Headphone issue. 

In other words im willing to concede defeat.

I have a Samsung QLED with the same ARC CEC issue: The Sonos takes over from the Bluetooth headphones within 2-3 seconds.  The lame workaround I use is to unplug the HDMI cable from the  back of the Sonos bar and then pair the BT headphones. Works fine, but not the way it should.

I have the same problem using Sonos Arc (HDMI), LG OLED C1 TV, and Bose Q45 headphones. The only way for the headphone pairing to stick is to unplug the Arc and this is not the optimal solution. 

Did this ever get figured out? Just bought a G1 and ran into this and now am frustrated.

This is a common concern with any device, including Sonos, that uses CEC. CEC is a standard that ‘allows’ a single speaker ‘sink’. You’d have exactly the same issue with any other manufacturer’s speakers, if they use CEC. See https://en.wikipedia.org/wiki/Consumer_Electronics_Control for more information. 

As has been discussed in many threads, you may want to turn off CEC on your TV, which is the controlling hub for that system. Most people find that doing that still allows the use of the Sonos, and leaves the optical port active that they connect their headphones to. 

Just got an Arc for my LG G1 and can confirm this is still an issue.  Definitely a Sonos issue as I also tried the latest Samsung Q990 and LG sound bars and the Samsung and LG bars both allowed headphone use with no issues.  Same TV, same headphones, different sound bars, all using CEC but only Sonos had an issue with headphones.  

This is still an issue. 

The same issue on LG G2+Sonos Arc.  Disabling SympLink(HDMI-CEC) on TV auto enable it back in few seconds with connected Sonos arc by HDMI eArc. Tried with TV+PS5 only, disabled SympLink(HDMI-CEC) , no auto enabling for SympLink(HDMI-CEC) as expected. Looks like either Sonos  or LG firmware handle HDMI-CEC wrongly.

It's few years for the ISSUE, no explanation neither from Sonos, neither from LG - SHAME!