Some router companies has been known to release updates to their firmware that causes issues to Sonos connections, but that may not be the case here, as I think the key phrase in your post is the fact that they play some period of time, then lose connection. That leads me to the possibility of duplicate IP addresses in the router, which is challenging to ‘see’ in most routers.
I’d at least suggest a WiFi refresh, by unplugging all Sonos devices from power, then rebooting the router. Once the router comes back up, plug your Sonos devices back in to power, and see if things are resolved.
I am having the exact same problem...can’t go for more than 1-5 songs before it abruptly stops mid-song, and then from the app I get a series of “can’t connect to product”, “device can’t be found”, etc.
My devices are in the same room, and less than six feet away from the router line of sight. All my other devices have robust wifi connections (150+ Mbps)
I’ve tried setting channels to low interference ones, I’ve tried turning off TWT and Smart Connect, and I’m nearing my wits end on these $700 paperweights...WPA2/WPA3 and OFDM are on, and I have 2.5 and 5 GHz SSIDs available.
Did you do the process suggested above?
Have you tried wiring one device directly to the router?