Odd. Have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it? Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

It sounds like the auth token being generated by Deezer isn’t being saved by Sonos properly. I’d think, if that was a system wide issue, there would be a lot more posts about it, but I may be wrong. I’d be tempted to reboot all my Sonos devices, as well as my router, just in case, before testing one final time and then submitting that diagnostic and then calling in.

I created a diagnostic and will try and call Sonos tomorrow. Thanks 

I have Deezer and it is currently working fine for me. 

Woke up this morning and Deezer was back in the Sonos app.

Nothing changed, as far as I know, and I never got through support.

Strange.

And an hour later Deezer is AWOL again.

There's a blues song in this experience.

Given that there have been no changes to Sonos, that certainly suggests an issue on the Deezer servers. Have you contacted them?

My Deezer integration is still working fine FWIW. 

I exchanged a few support messages with Deezer they say there are no issues on their end and, as the speaker connections I have in place work and the Deezer app plays ok on my phone, I have no reason to doubt them.

The issue is odd as the speakers have no issue staying connected it's just the app. The app connects, works perfectly then drops the connection when the phone goes into standby. I think it is still connected otherwise it would not have randomly worked this morning.

If no one else is seeing the issue I'm going to wait for it to self heal like it did this morning. Hopefully next time it will stay healed.

Maybe rebooting your phone might sort it? 

Tried that twice now.

Sign in at Deezer.com → Account Settings → My Apps (or connected apps) → remove/revoke Sonos. Then re-add Deezer from the Sonos app (this clears any stale tokens on Deezer’s side).