The first thing I’d try is removing Spotify from your Sonos system. Then I’d add it back in, which would force the Sonos system to reach out to Spotify, reauthorize itself, and grab all the associated data with your Spotify profile. 

If that didn’t work, I would call Sonos Support directly to discuss it.

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 network and Sonos system.

It worked, thank you very much Bruce 

Now, if only I could explain why it ‘lost’ the data….but  I am glad it worked ;)