I was using the unofficial sonos controller to play music from the music library whilst I had a YouTube video playing in the background. I had the two sound sources playing simultaneously at start but for some reason after quitting the USC app my other sound sources no longer play any sound. Relaunching the USC and playing music again works, but no further sound from the other sources on the system - no YouTube playback and no system sounds either ... rebooting the system completely does not fix the issue. Only unplugging and re-plugging the Sonos Playbar's power cord recovers all the sound sources by default...
I was using the unofficial sonos controller to play music from the music library whilst I had a YouTube video playing in the background. I had the two sound sources playing simultaneously at start but for some reason after quitting the USC app my other sound sources no longer play any sound. Relaunching the USC and playing music again works, but no further sound from the other sources on the system - no YouTube playback and no system sounds either ... rebooting the system completely does not fix the issue. Only unplugging and re-plugging the Sonos Playbar's power cord recovers all the sound sources by default...