Same here. Very aggravating. Diagnostic report 490235596. 

This used to be an issue with some TV’s, particularly with Samsung and connected sound systems using HDMI-ARC/eARC, where other connected peripherals like Apple TV (as an example) tried to steal the CEC focus.

So maybe try disabling CEC on any other connected devices and then power off all for a few minutes to setup the handshake again and see if that perhaps solves the matter.

We had a similar issue with our LG C1 and the Arc.  I changed the sound output to the TV speakers and then back to eARC.  That seems to have cleared up the issue here.

Not sure if my issue is the same.

I have an ARC, LG Oled and Apple TV.

Watching source from the TV apps, the audio randomly drops off for a few seconds and then comes back.

Happens once every few days.

Not sure if the ATV does it also.

Have you submitted a diagnostic and called Sonos support to see what data their might be in it? 

I will once it happens again. I was told need to collect it within 10min of problem.

I *think* that is generally accurate. Not sure exactly how much data is stored in a diagnostic, since I have never seen one, but I’m sure that it isn’t infinite. And unfortunately, no one has access to that data except Sonos employees, so most of us are guessing based on previous experiments and successful resolutions, without seeing any hard data. 

Same problem for me, the sound cut few seconds every like 15 min + a big bzzz sound happen when there is no sound for a moment and a sound occur… e

I'm connect for my pc Gpu (RTX3080) by hdmi 2.1 (8K) to LG CX, then to the sonos arc (earc hdmi 2.1 provide with the arc)

It is really annoying !!

Just had this happen today for the first time. Sound dropping out for a few seconds every 10 mins or so, sometimes with a crackle/pop noise. When I tried to get into the Sonos App it seemed to be offline, saying the system and app we're on a different network apparently. The only thing I can think of is it somehow connected to my mesh node at the other end of the house which could of confused it, and would be a weak signal, no idea really. I'll monitor it and hope it's a one-off and doesn't happen again (app is back to normal now).

Incredibly disconcerting that this problem hasn’t been resolved. My Arc is barely three weeks old and had this issue almost instantly. 
 

I’ve submitted various diagnostic reports to Sonos and the best solution I’ve been recommended is to factory reset our system, which I haven’t had an opportunity to do yet. 
 

Unless there is a dependable fix soon, I might have to return the arc. 
 

It’s bonkers to me that this issue can go so widely reported and a solution hasn’t been found. This thread started around 2 years ago!

Had this for about a month now. Very annoying. Resetting the whole system has been done without it doing anything.

Got this sorted on my system. I swapped out my HDMI cable. 
 

I went all round the houses only to discover it was something so simple. ‍♂️

Good tip. Will try that as well.

So you swapped the original hdmi 2.1 cable equipped with your Sonos with a new spare one?

Was the original cable from Sonos the faulty component?

If yes, please tell me: haven’t ever tought that could be the problem

tnx

Where did you put the adapter? Between the TV and the Sonos?

Tnx

As it happens, I made the classic mistake of not using the HDMI that came with the Arc, but used my pre-existing one which was a very high quality cable. I thought it supported 2.1 but evidentially not. I haven’t had a dropout in over 2 weeks since changing the cable. Maybe it’s even three weeks. 

Replace HDMI cable exact same issue from start of purchasing the Arc (which has been 2 days). Replacing HDMI Cable fixed the issue (been 2 hours since it cut out before doing this cut out happened every 15-20 minutes), its an easy fix try it.

I have had the same issue with my arc going offline and coming back I have tried changing the hdmi cable , hardwired the arc changed to sonosnet and lastly wifi with no fix . 
the idiots at Sonos can’t help even keep making me do nonsense again and again till I gave up with those morons at Sonos . 
it’s a shame Sonos have hopeless engineers and for the rubbish support that we get without a fix after wasting our time and efforts doing all their stupid R&D . 
I use to promote Sonos and sell them but after this no more because of their idiots whom wasted my time for over a year and not even bothering to do an RMA to my rubbish ARC . 

More likely it’s a TV issue with its version of hardware or CEC protocol - very few ever complain of this issue - I guess the most reported is with some Samsung models of TV’s but I guess any TV can be faulty. I would expect everyone to be complaining if it was the Sonos HT product and myself and Son-in-law (and a few friends) use an Arc and we’ve not encountered the issue mentioned, so I would maybe look closer at it perhaps being the TV.

Hi Ken_Griffths

i had also done that test by disconnecting the hdmi from the tv for a weekend and monitor and it happened so tv is also ruled out. 
it’s been a year plus I have finding a solution because Sonos support sucks and till they don’t open an rma I can’t do much . 

Assuming that you’re no longer using SonosNet, what 2.4Ghz channel & channel-width are you currently using with your router? What’s the current SNR reading for your Arc in the Sonos App (Arc room settings - see this Link) and last, but not least, what is your internet download/upload speed average readings from your ISP?

For 2.4 I have used ch 1,6 and 11 

speed is 200 plus up and down wifi

 Using a unifi udmp and Ap’s all around 

In that case see this link…

https://github.com/IngmarStein/unifi-sonos-doc

Hi Ken_Griffths
have checked the link and all settings are as recommended. 

What’s the SNR reading showing on your Arc - is it well above the 25dB level?

Can you describe the setup in a little more detail too please - both the Network and Sonos and is it a case the Arc disappears just from the controller App, or is the actual audio dropping out. When the issue occurs, does the Arc show as still having an IP address on the LAN? What happens with its status LED, if anything?