No sound from Sonos PLAYBAR based zone using Spotify

[user-removed]

Has anyone out there had an ongoing no sound problem with a specific Sonos zone using Spotify?  I have a three Sonos zone setup, one using a PLAY 5 (Living Room), one using a third party speaker linked via RCAs to a CONNECT (Bedroom) and one using a PLAYBAR, SUB and two PLAY 1 speakers (Den).  

Since (coincidently or otherwise) linking Spotify to my Sonos account I can play Spotify through the Living Room and Bedroom zones perfectly well all of the time.  However I cannot get sound through the PLAYBAR based Den set-up.  All other Sonos functionality is OK (Music Library and Radio by Tunein) in all zones.  However, when using Spotify through the Den zone the sound meters funtion indicating there is a signal, but there is no sound.  The only work around I have discovered is if I link the Den zone to one of the other zones using Spotify, it then works fine!  I can subsequently reduce the volume on the other zone to silent.  If however I then delink the other zone, the Den zone goes silent again, even though the signal is still flowing.  Frustrating!  

This problem is persistent and ongoing.  I have not been able to use the Den zone with Spotify at all since the partnering of Spotify and Sonos.  Applemusic worked fine, but I not longer have that service.  Also, this problem persists irrespective of what Apple based controller I use, be that Macbook Pro, iPad or iPhone.  

The only other clue I can offer is I get a message sometimes when testing the Den zone saying "Unable to play (Song) the connection to Spotify was lost"  

Any suggestions to resolve?  I'm stuck.  

Thanks

[user-removed · Accepted solution]

So, coincidently or otherwise, today's Sonos update has been installed, my PLAY 5 zone (room) disappeared, I reinstalled it and now everything works fine.  Sonos troubleshoot post resolved.