FYI, Currently (for the last month) it seems that Sonos is having issues even within their own systems. Reports of some players in a system not even being able to play audio!
We've also seen multiple sites with 2 players in the last month where one player will work fine and the other is completely non-communicative...
Digital music is a Crap-Show and as I said earlier... ?The 'Digital age' is really embarrassing...