the issue occurred again :( 

Sorry to hear that… When the surrounds do go offline, are you able to still ‘ping’ their IP address to see if they are still connected to the LAN, or do they actually briefly lose their LAN connection? Also have you had chance to contact/chat to Sonos Support Staff to see if your diagnostic reports show any issues?

Yes they are definitely still connected to the LAN. In fact if I go into that app and toggle surrounds or subs off the slow blinking green light appears (indicating they are disabled) which implies there is still connectivity. I just get no sound from them until I power cycle 

sonos support merely said there was a network issue according to the diagnostic and had me power cycle everything 

@peterbault,

I would suggest changing the HDMI cables involved, or at least powering off all and reseating them? Have you already tried a factory reset of the main HT player (only) too?

You can always go back to Support if the issue persists, they may be able to advise you what to try next… it might be one of those intermittent issues that may show up in a further diagnostic report.

@peterbault,

As a further thing to try, have you considered switching off CEC on the Apple TV and all the other devices connected to the TV over its HDMI ports?

I think that’s perhaps worth a quick try too, as it could be something interrupting the A/V connection/handshake and is trying to steal the focus away from the soundbar, causing it to revert to PCM stereo output only. So maybe try switching off CEC on any connected devices and just see what happens.

Infact what I don't understand is that many of us have had the same problem since 14.6 but we are told to do this or that, when it doesn't change anything!!!!

I go home, I listen to 3 songs on Apple Music, and I lose the Sub and the Surrounds! And then they will tell me that it's because of my TV (jz1000 from 2021) or my HDMI 2.1 cables... it's your Update!!!!!!

Infact what I don't understand is that many of us have had the same problem since 14.6 but we are told to do this or that, when it doesn't change anything!!!!

I (and a few others here), are just trying to help with some suggestions, quite simply as Sonos users ourselves - clearly not everyone has this surround dropout issue and it’s ‘perhaps’ sometimes better to try a few things, than just sit there and wait for the next Sonos update, in the hope that it provides the fix.

You don’t have to try these suggestions of course, that’s entirely a matter for yourself.

I appreciate all your help and suggestions @Ken_Griffiths 

If it was the Sonos software, wouldn’t it be affecting everyone, rather than a few separate people? It seems, from the outside, like there’s some sort of network issue, which could be different in different cases, which is why working with Sonos support is likely to be more helpful.

I have two installs, and ‘manage’ three others, none of them are showing this behavior. That leads me to the conclusion it’s a local, not endemic to Sonos’ software issue. But since I don’t have access to any diagnostic information that tells me one way or the other, my opinion remains that, just an opinion.

it's very nice of you, but Sonos annoys me a little, I have the impression that for them, it does not come from their update. I was at Bose and I decided to come to Sonos for 6 months, and when I see that, it annoys me! at the price it costs!

explain to me why it works badly since the update ??? even if it's not for everyone, there is a problem with this update for some people!

you are way too complacent on this forum!!

There are lots of different set ups and equipment t out there (TVs, HDMI devices, network characteristics, etc) it could be a bug that only affects a small subset of configurations

Certainly possible @peterbault , which is why I tend to suggest that Sonos’ ability to read diagnostics overcomes any mental image we have of the systems that are afflicted. 

I’ve changed HDMI cables from TV to Sonos. Gonna see how it goes 

I’m certainly not complacent @Flo14000 - I just like to at least try to explore the issue thoroughly (with others here) before jumping to any conclusion that a Sonos software update is at fault. If it is the software, at least we are able to demonstrate here how we reached that conclusion constructively, by trying the obvious suggestions first.

the problem really appears when either you change the HDMI source, or when on the Apple TV, there is a change in video format (like we go from 24Hz to 50Hz) I don't know if I'm being understood! but i noticed this. Using TV apps, I haven't had a problem so far.

Yeah, this was why I was mentioning as much of my configuration as possible, to see if it possibly had to do with the other devices on my system and if there was a pattern with others.  @Flo14000 , similar to you, I’ve noticed that the majority of the time I’ve lost my surrounds when I’ve changed my HDMI source.  When I’ve watched my Apple TV for a long time, for example, I never notice that the surrounds just shut off.  

Still befuddled, however, on what the bug is.  

yes, I can watch a movie without having the problem. there problem will arise by changing the source. example: on the same video clip on Apple Music, I launched it several times, and after a while I had the problem. and even if afterwards you try to listen to music via Sonos S2, the problem is still present. once you lose the sub and surrounds, it ripples through any content. the only solution, cut the power to the Arc.

I change my source device daily flipping between apple tv,pc and xbox series x 

Never had this issue my apple tv is on 15.5 and set for matched frame rate and other devices at 60hz for pc and xbox 

I haven’t been able to reproduce it after changing the HDMI cable. Still too early to say it’s for sure fixed though. 
 

I wonder if it was some CEC issue that could be resolved by unplugging and reseating they HDMI cable 

I’ll update again later 

Nope there it goes again. :( 

That’s a shame - next thing I would try is to switch off ‘CEC’ TV/Receiver control on the Apple TV and on everything else connected - or simply unplug all from the TV, except the Apple TV (with No CEC) and the Arc/Surrounds and see if the issue still then happens.

By the way don’t forget to take a diagnostic report (if practicable) and note it’s reference as that may be important later if you need to go back to Sonos Support.