Probably an issue with your speakers reaching the Spotify servers, due to some sort of wifi interference. You may want to submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

I’m curious if this could be the problem as my daughter can get her Spotify account to play through the Sonos without difficulty? 

I did ‘REAUTHORISE’ and within hours my Spotify account had been hacked, its email changed and some 400 songs placed in my library.  Took hours to sort out. My mistake was  probably using same password for Sonos and Spotify. HAS SONOS DATABASE BEEN HACKED????

Or your phone?

Yes. Used phone for that purpose.

No problems with phone.

I’ve not seen anything that suggests that the Sonos database has been hacked. All caps or not….