I’ve been chasing this S2 app issue for months (years?), with most of my time spent optimizing my Unifi network settings, using SonosNet and not, etc.
Lately, the issue has been plaguing my phone but not my ipad, and I just had an Aha moment. I toggled off cellular, and my speakers appeared instantly! I then toggled off cellular access to the Sonos app, and so far the app is running fine. Fingers crossed this is the final hurdle for me.
Wondering if anyone else can reproduce this issue. Sure seems like a bug to me.
Cheers, Stephen