Lost surround and sub ( after update ?)

I am loving this “disable/enable wifi” trick. It’s basically an unofficial restart function 

I’m starting to think broader. There must be errors all the time with HDMI systems when CEC/source/format/codec switching. Maybe 14.6 introduced a behaviour that somehow latches when there’s an error and discards some audio when before the system just recovered better on its own. 

Yeah, I see where you are going. But (for me) I have been unable to reproduce the issue using the Native app to play Netflix and Amazon Prime. But, who knows, perhaps I did not test long enough and maybe its the way Apple have that Dolby MAT thing.

I was forced to upgrade my Sonos today as it stared disabling features until I updated! I dont mind that much, but its really meant that I now have inconsistency during testing. 

like foxis, I think the problem comes from Sonos at the audio codec level. in any case, the solution of deactivating the Wifi of the arc (if it is wired) is a better solution than unplugging it. I'm glad to see that the forum continues to grow! and again, OK we do diagnostics for Sonos, but a company like Sonos is therefore not able to do the tests themselves? it's pretty amazing, it's been over a month and still no update solves the problem!

Yeah I have tried that an no joy for me like Peter unfortunately. 

The Engineer seems focused on the CEC error - he says that when my system loses the subs and surrounds (from my many, many diags I sent) this error is present and its not expected. He said the other  device connected to my TV is set to TRUE - and that would be my Apple Device as its the only device connected to the TV bar the ARC.

It’s great that we might be finally getting some traction with Sonos support but a big benefit of this forum has been finding work arounds to make living with this easier while we wait for a fix. This is the best one!!!

Edit: NOPE didn’t fix it

 may have discovered something *knock on wood*

Since @Brad Porter gave me the idea of using trailers on amazon prime to force the issue, and other folks chiming in about browsing netflix and the auto previews causing the issue I’ve been able to confidently and consistently reproduce the issue whenever I try new fixes.

Also, all of this CEC talk got me thinking from a different perspective. I basically went to my Sony A9G’s audio output settings and starting turning things off one by one. I was always able to reproduce the issue until finally I tried turning off “A/V sync”. This has 3 options on my tv: “auto, on, off”. It was on auto, just to test I turned it off. 

I went through my testing of going between various content in 5.1, atmos, stereo, then played the contractor trailer (thanks @Brad Porter I will never ever want to watch this movie now) on amazon prime, and then went to netflix and just started browsing. I did this for about 30 minutes and the issue never occurred. previously with this process I could get it to happen within 5-10 minutes. Thinking about the point of this feature if something changed with the Sonos software unintentionally to affect this it makes sense with the symptoms we’ve all been having (changing formats, switching frequently, CEC theories, etc). I’m also not sure if everyone experiencing this has an equivalent setting on their TV?

Maybe just a fluke? I’m leaving these settings as is and will monitor through the evening and keep the thread updated. I’ve included some photos of the settings:

FALSE ALARM: it finally just happened again sorry everyone 

O dear. Not good.

@ peterbaultcongratulations to you, you've been there since the beginning, you always try to find a solution by all possible means, it's nice to have someone like you in the forum!