Some of the older Sonos may be at the end of life for the internal memory, power cycling can mask that for some time.

I'd submit a diagnostic after it has been powered up and playing for over 15 minutes then call Sonos with the number to have the hidden interna data looked at.

Thanks very much for this recommendation.  I’ve certainly gotten a lot of life out of this one, but I’ll give this a shot to see if there’s anything I might do!  

The older Sonod devices are having a hard time keeping up even if you use the S1 app. I had my p 100 hardwired to my network and never had an issues with it.

If you still have a Bridge, you may want to try removing it form your network and hardwiring a Sonos device instead to see if that solves your connection issue.

Thanks - mine is also hardwired to the network, and I dropped the Bridge a while back...if it is on its way out, almost 20 years is pretty good!  

That's a really good run! You may be a candidate for a new Amp. Luckily the Amp is compatible with both apps.

https://support.sonos.com/en-us/article/sonos-app-version-compatibility