Copied from a similar thread on Sansungs website:

“I got today the confirmation of Samsung that Sonos and Samsung work together on the issue. A software update can be expected in March according to the Samsung Support.”

Thanks for the update, much appreciated!  Crazy you had to update us and not Sonos jumping in on this thread.  

Guys,is there a TV that actually works with Sonos Arc for ATMOS? So far it seems like LG, Samsung, Sony, Panasonic, TCL, Hisense, Vizio all have issue with the Sonos Arc with audio cut out issues and no fix available yet. Is there even a TV that work for people here?

My LG C9 TV is working fine here and I get Atmos output.

Yep..my Sony works great. Sony came out with their firmware update a couple of months ago...no issues.

I recently went through the trouble of updating the software on my 2020 Samsung Q80T to 1460 (not sure why but only available as a download to a USB stick). Seems to have made the problem worse. Changing channels on YoutubeTV drops sound. I doesn't come back unless I either change the audio source on the TV and then change it back to the Arc, or change channels and change back (this sometimes works but not always). So Samsung does not seem to have fixed the problem yet, and haven’t seen a Sonos software update is quite a while, leading me to think that Sonos has taken the position that its not their problem. 

I worry about these updates that show up for download but not pushed over air.  Feeling like we’re getting test versions.  If it is worse than previous, can it be rolled back to previous version?

Well it seems LGs recent 3.21.09 and 3.21.16 firmwares for CX/GX  have improved the issue, I would go as far as say its fixed the issues, but I only installed the firmware the other day so can’t say for sure.

Although the firmware notes do not state audio/eARC fixes I believe the firmware does contain fixes for audio issues, Ive seen a lot of owners say these firmwares have fixed their audio issues.

I’m sure I read somewhere on AV Forums that the issues on this thread seem to be mostly happening on all of the 2020 models like the LG CX, Frame etc rather than the 2019 C9, something to do with how eArc was set up on the earlier model.

I am going to get on to Sonos support today and hopefully they can help as I am getting nowhere with Panasonic, they are saying it is down to the the way Netfilx, Prime etc configure their apps its not Panasonic. Everybody passes the book to somebody else, its depressing!

This may help/may not. If you have Sky Q, change picture settings to 8 bit. I get sound interruption if set at 10 bit. Wierd...

1460 appears to have pushed over air for Frame.  Folks seeing any improvement?  I still have to restart Sonos with 1460. Seems it still can’t handle a audio stream start, like tv coming out of sleep or art.  But can reboot into an existing audio stream. 

Having 1460 on Samsung Frame with sub and play 1. super disappointed that this is working faulty and even more to see it is known for almost a year now. Sorry Sonos...we spent good money for your system, go figure and solve it. Be customer-focused please 

I have a Samsung Q70 and have random issues when changing between Netflix, Youtube, TV etc. the sound just drops out. Usually have to unplug everything to get it working again. 

I am having the same issue.   Have an LG OLED55C6B.   Had arc less than a week and sound just stops completely and reverts back to TV speaker.  
 

not what I expect from a sound bar that is nearly £1k.   

I have a 2020 Samsung q60 and the arc was working ok for the first week then started to drop off sound occasionally especially if I listened to music through airplay. Today, however, it stopped working completely. I have unplugged and switched off from the plug more times than I can remember and still nothing. It also overrides the tv sound so even when I want to switch to tv sound it won’t allow the tv to do this. Any help, much appreciated.

Ken,

What LG firmware are you on and do you have eARC set to on the C9 menus? Also are you using the apps on the LG to play or sourcing elsewhere? I’ve been having drops on my C9 (latest firmware) when I have eARC set to on. 

LG firmware is 5.00.10 and eARC is on and the HDMI ports are set to pass-through. I use the in-built Apps Netflix and Amazon and Rakuten TV and also use an Amazon Fire Stick 4K Ultra HD… I’m about to add a Nvidia Shield TV to the setup too.

Hope that helps.

Thanks. That’s exactly my setup (- Fire Stick). I’m certain it was all working up until about Christmas time then I started getting drops and not just on Atmos content. Turning eARC off fixes it but obviously will restrict me to non-TrueHD Atmos content. Maybe I’ll turn it on again and see what happens...

Just to add, I use the network adapter add-on for the Amazon Fire-Stick, so mine is actually wired to the LAN - I didn’t bother to take the chance of the possibility of a poor WiFi connection or interference, if that assists further at all…

www.amazon.co.uk/Amazon-Ethernet-Adaptor-Remote-models/dp/B01LXP5TXI/ref=sr_1_1_sspa

Thanks - I’m ethernet all the way here. If it doesn’t move, it gets wired...

Yeah still have this issue on my Frame TV - its crazy the number of manufactures this affects…some have patched it and some haven’t.

Ok so it looks like I may have bottomed out the issue with the help of Sonos support and thought I’d update on solution here. I have my LG C9, Sky Q, Arc and Sub all connected via ethernet to the same ethernet switch. Support suggested I remove the ethernet cable from the sub and rely on the 5Ghz connection between the Arc and Sub. Not a single dropped earc/passthrough connection between the C9 and Arc last night. I suspect the underlying issue might be that I’d created a loop in the network. Although I’ve no idea why Netflix on Sky Q never dropped but C9 (and Apple TV 4K) Netflix did. Maybe bandwidth...

I had a similar issue many years ago where I had a bunch of ZP100’s hardwired. Loops were creating network storms and the solution was to use an ethernet switch that supported spanning tree and configure that appropriately. Hope this helps someone else out and my my setup stays stable.

Give it some time - there really shouldn’t be a reason that a network storm would affect an HDMI connection.

NOW - that being said… I could see an issue where perhaps network congestion while streaming could cause the streaming service to automatically switch from an atmos audio stream to a standard stream and the TV or ARC didn’t notice the change in format…...but you would also probably get some very bad video buffering / freezing.

Which indeed I was. After 2 or 3 disconnects, Netflix would hang...