I used Sonos 1 for years and never had a problem with the app.
I upgraded to Sonos 2 last summer and the app needs to be reset every week - it’s really annoying.
It says it can’t find the system, then the diagnostic finds it, then it asks me to switch the port and the speakers off and switch them on again.
I’m using an iPhone 11 - the app my 6 year old iPad doesn’t seem to have the same problem and can always see the speakers - I’ve restarted the phone and the problem persists so I don’t think it’s the phone that’s at fault.
Some times the app then just finds the speaker an hour later - even though I did nothing - just gave up - another reason I think t’s the app not the phone.
Any ideas ??