I have the same issue!!! Close the app and switch phone off etc in the evening.

Switch phone on in the morning  and open the sonos app and get the message " no products found". I have to close and open the app several times before it finds " products"

Infuriating 🧐

I have the same exact problem.  The iPhone app connects to my system and within a second or 2 it says there are no connected products.  You have to close the app and reopen it to see the system but soon it disappears again.  The Mac app and play.sonos.com on a computer work just fine.  It's just my iPhone app! help!

I reset the network on the app for my 5 WiFi connected speakers and it seems to be working now.  4 of them I was able to reset on app the other one I had to do a hard factory reset.  The other 6 zones are hard wired so I didn’t do anything with them.  Let’s hope that this is it