I've been using Sonos for maybe 5 years. I sometimes unplug some rarely used players. (I know I'm not supposed to - too bad, I do).
When I boot one up, it takes forever for the controller to see it. I almost always force-quit the controller and launch again.
Sometimes the controller takes forever to "sync" with what I'm playing. I launch the controller and it shows what I was listening to an hour ago. If eventually see's what's going on and shows me the right stuff.
Or I go to play a new album and it says "queue has been edited, do you want to continue?". Yeah, I know it was edited by my wife, but why does the controller only realize this after I try to play something".
It's like whatever logic the controller has to query to Sonos and get the current config takes minutes instead of seconds. And while you are in that state where the controller isn't in sync there is no visual indication, it just acts funny.
Suggestion - make it sync faster. And make it show some "synching" indication while it's still doing it.