Why the paranoia? Of course Sonos are doing nothing of the sort. How stupid and devious do you think Sonos is?It will be an issue with your local setup.

The first thing to try is to power cycle your router and all Sonos devices .

Stupid or devious? I guess it’s one of the two. There has to be an explanation for why the Sonos systems are so fragile. While I might be paranoid, I’m not the only one to be frustrated by Sonos. There is a lot of dissatisfaction out there.

Anyway, thanks for the suggested solution, though it hasn’t worked so far.

Stupid or devious?

Actually, I guess it could be both.

Since the only speaker visible in the S1 app id the only non-S2-capable in your set up: has anyone performed an upgrade to S2 on your S2-capable speakers?

I did this 6 month's ago not realizing that it would exclude the Play 5 gen 1 speaker from the system and then had to row back with speaker resets etc to get back on the S1 app which supported all of my speakers. Now the S1 will not allow the Play 5 at the same time as the Play 3s. It does work with the Play 3s. I shall probably sell the Play 5, the going price for which has, as you would expect, plummeted.

As has been said earlier: Sonos isn't doing this. There's either something wrong with your speaker or in your network. If you want to try to get a solution for this: call Sonos.

106rallye, and John B, you were right. I followed your advice 106rallye and spoke to a very helpful Sonos representative (in Transylvania of all places), who talked me through the relevant update. The update was to the S1 app not an upgrade to S2. Unfortunately, it was not available on my phone since the phone's OS is no longer supported by Sonos, being Android 7. Hence, I had to install the Sonos S1 app on my wife's iPad and update the system on that. The whole thing worked pretty smoothly after that. And now the system works on both my phone and my PC though I will not be able to update on either of these devices, only on the iPad or some other fully supported device.

So, you were right about this not being a conspiracy on Sonos’ part, John B,  but simply part of the update churn. John B. Thanks for your advice and apologies for being dismissive of it in earlier posts.

...And you were right about it not being deliberate on Sonos’ part too, 106rallye. Apologies to you too for my sour response to your earlier message.