So here we are, two weeks in to the S1 rollback. 
 

I’ve had one 8s dropout at the end of a track and that might simply have been a Qobuz issue or a buffering issue as it was the first track on play after being paused from the night before and the track played out the last 8 seconds in the app but without sound - and the next track cued up and played fine, including sound out of the amps. 
 

But as ever, the apps remain responsive and quick to find the connect amps (S2 was terrible for this). Playback (apart from the 8s end of track dropout) has also been seamless and glitch free.  

Adding my name to the pile of folks who are having this exact issue.

I don’t think an S1 downgrade is viable for me, because my system has a handful of Roams in it, and I don’t want to lose the ability to group them together with my Amp.

Add me to the list also.  This is a software issue, IMO.  OP has it dialed here:

“So it seems to me that Sonos have released a firmware update that the connect amp cannot handle, and rather than take responsibility for it, they're just fobbing people off telling them to buy expensive new hardware to solve the problem, not even with any substantial discount. It's unacceptable. This connect amp worked perfectly before June.”

Another update. 
 

The system has now passed 400 hours of continuous up-time since the S1 rollback. 
 

Everything continues to run as it should. 

We are a Sonos dealer and have been having this same issues for several months now on multiple systems with Playbars and/or Connect Amps.

We have made every recommended network adjustment; wired the devices, set 2.4 to 20MHz, reserved IPs, separated the network and SonosNet channels, tried turning 5G off, etc. nothing has worked permanently.  What we have found is that after rebooting all Sonos devices, they work fine for about a week to 10 days, then the problem starts up again - this has been fairly consistent. Sonos support has looked at a few of the systems and saw no issues in the logs. 

This is NOT a network issue.  I have seen Corry P (Sonos staff member) acknowledge on a few different Sonos Community pages that this is a Sonos issue and I have also spoken with our Sonos rep who has acknowledged this was an issue created by a firmware update that they are treating as a high priority.  There is no ETA yet on the resolution.

I’ve just spent some time on the phone to Sonos support and this is the bottom line re the Connect:Amp audio dropout issue …

Telephone support was more productive than the chat support who just follows a level 1 script and suggest things that for this memory issue will never make a difference (eg changing wireless settings on speakers, router, etc), when my Connect:Amp is ethernet connected anyway.

Telephone support acknowledged the memory problem with this Connect:Amp device but I don’t believe there will ever be a resolution. Sonos continue to develop the S2 software and the smaller memory in the older devices eg Connect:Amp will never be enough for the growing requirements of the software.

They suggested trying things like removing linked subwoofer which even if it worked (which I doubt), is not an acceptable fix. My Connect:Amp and ceiling speakers need the subwoofer.

Unfortunately the only true ‘resolution’ accepted as much by their telephone support is to replace with the newer Sonos Amp with its greater memory specification.

This is the official reaction from Sonos, a pinned reply earlier in this thread. All the rest is gossip and hearsay.

Did you read the pinned reply?

Of course they didn’t, it’s a stupid AI post with a Spam link embedded.

Ah, I didn't see that.

Not gossip or hearsay in my case but based on a phone conversation with Alexandru at Sonos Tech Support. I’d like to think Sonos engineers are currently investigating this with the highest priority (as it says in the pinned reply), but unfortunately the message I took away in as many words, was that it’s an old device, they don’t have a fix and you’ll have to upgrade to an Amp .. or just periodically reboot your Connect:Amp to clear down memory.

The following are not their words, but I don’t believe they’re investing any effort in trying to fix this issue in something they’ve effectively declared end of life. The changes they’ve introduced over time with new functionality etc  and that require more and more memory can’t be undone.

If you think Customer Support is in any way aware of what Engineering is doing at any time, you’ve never been in an Engineering department.  I’m a software engineer, and in the last 20 years I can count on one hand the number of times I’ve even spoken to Customer Support, and it’s never been to tell them what I’m working on.  CS puts a ticket in, and that’s the entirety of our interaction. 

Very old school. You’d hope in this age there would be better systems, collaboration , but going by experience with support you’re probably right. Gives the pinned reply even less credibility.

No, the pinned reply is official, so it was vetted before posting.  In my experience, half of what people claim to hear from CS is imagined or twisted to fit an agenda, and the other half is CS just trying to get an irate customer to shut up (or hang up) by saying what they want to hear.

One thing is for sure, the technical know-how of your average CS rep is equal to the technical know-how of your average person on the street.  Nobody hires a low-level CS agent for their intricate technical knowledge.  They read scripts, that’s it. 

Hope you’re right but I won’t hold my breath.

S1 rollback update - 

The amps have been continuously powered up now for over 550 hours and the system, connections and associated control apps have all remained rock solid stable and responsive. 

Good to know as an option for those where S1 rollback is an option, ie compatibility across the system.

Another option for those that do not or can not go to a S1/S2 split system is to power off the Connect Amp after every use - based on what is written here, it should work ok on S2 when powered on again for music play. 

I do this with all my Sonos units anyway, and this may work for those affected till Sonos delivers a better solution or the amp is replaced. From what I have read about the issue, I agree with Steve about not holding ones breath for a solution using the same hardware.

When I was running S2 on the amps, powering them down worked for a very short period of time before the dropouts returned and it didn’t prevent software or app glitches occurring, sometimes within minutes. 
 

The dreaded ‘unable to connect’ was the prime culprit and using multiple devices to control the amps was asking for trouble as it seemed that the amps were only capable of been seen by one control device at a time. 

Having seen what is on another concurrent thread on the same subject, which suggests that other older units may be the next to be afflicted by S2 memory usage, I am reminded to be glad that I elected to stay on S1 four years ago when Sonos enticed us to move to S2. At that time I had all my rooms covered and had come out of the want more Sonos trap, so I had no pressing need to keep marching with Sonos on S2. I also discount any chances of sound quality improvement to my units via S2 where music play is concerned and a side benefit of staying on S1 is to receive very few updates - indeed those can even be ignored with little consequence to the listening experience. And no risk of memory getting filled up on my 2011-2014 Sonos acquisitions.

I’ve had this issue (as other threads) & found the boxes perform ok for a day to three after reboot.  Unplug for half an hour…  and all ok until… very odd.  (Been through all options / can’t downgrade as other newer kit etc.  One my s2 connect amps was bought to replace an S1 model!)

Haven’t looked before (and I hadn’t been logging in here of late) but I see the Speakers forum is littered with people with older kit who have exactly the same issue. (Systems fine for years until recently….  No interference /other changes…. Gone through various hoops to attempt to resolve….)

I think what @britcowboy is trying to gauge, like many of us, is what is the realistic likelihood of a fix from Sonos for this memory problem ? 

In the absence of a fix, the alternative is to upgrade to the newer Amp and obviously, Sonos would prefer that route, but for many, especially those with multi-room, multi amp setups, this may not be viable or at least there will be some reluctance whilst a fix may be in the pipeline. It would be very frustrating to spend out on a new Amp only for Sonos to release a fix for the Connect: Amp shortly afterwards.

My feeling is that the longer this drags on, the less likely Sonos will want to continue investing more time and money in supporting the older kit.

Thanks for pointing this out. It seems that Play 3 is particularly badly affected too. 
 

So much for all the naysayers who said that there was no problem and that if there was, there’d be lots of reports. Well, there are when you take the time and trouble to examine and amalgamate the individual cases rather than dismissing each one as an isolated environment or network issue.

In defence of those dismissing the issue: it is based on their extensive experience that over 99% of issues are down to the network, so they tend to miss the less than 1% when that comes along.

In general: I don't expect to see a fix to this other than what has been seen to reliably work, a rollback to S1. And I don't think Sonos themselves expected to see pre S2 hardware survive for so long, by underestimating the build quality of their own hardware! If they had they would have not allowed old kit to move to S2 in 2020. 

Speaking for myself, I have never seen Sonos as anything more than quality amps/speakers and have never expected S2 or such to better their sound quality beyond what made me decide to buy them. The decision to stay on S1 was a no brainer, therefore. I did not buy Sonos thinking it is a networked computer that also happens to play music. I just wanted good sounding kit that did what my legacy HiFi kit could not do - play music from the internet. And that I got from Sonos via S1 and continue to do so.