My Sonos is back to normal. CAVEAT: I always stream vvia music services not a local library/playlist. What'd I do? 1. In Sonos App settings, DELETE CACHE, DELETE DATA (do BOTH). 2. DELETE ALL Sonos APPS (old S1 Sonos + the new app). 3. DEREGISTER ALL SPEAKERS from all music services that required it (i.e., Amazon). 4. DISABLE SONOS SKILL on Amazon. 5. REINSTALL SONOS APP (be sure to DISABLE AUTO-UPDATE after this fiasco) 6. RE-enable SONOS SKILL. 6. Add speakers and all music services anew.