Perhaps try setting up the Sonos/Google sharing agreement again in the GH App by selecting to ‘check for new devices’ from the Sonos Action/Skill as shown in the attached image.

Also ensure your Deezer account is added to the GH and Sonos App and that both are logged in with the same credentials.

If that still fails then perhaps try removing the GA from the speaker itself and re-add it back to the speaker via the Sonos App.

Also don’t forget to set Deezer as the default music service in the GH App as per attached screenshot.

Thank you for the recommendations Mr. Griffiths.  Great ideas, but no joy.  Interestingly, I have just observed identical behavior at a second house.  This suggests it wasn’t just some local glitch, but rather something external.  My bet is on GA.  The quest continues.  I will post here if/when I find a solution. Have a great day.

@papril 
That’s okay, there have been some GA reported outages in some community posts recently, but most appear to be Alexa related with the occasional GA issue thrown in, so maybe it’s that?

Oddly, both Alexa and Google Assistant are working okay here with my Deezer HiFi subscription - so perhaps if the problems do persist, you might want to submit a system diagnostic report and make a note of its reference back here and then perhaps contact Sonos Support via this LINK.

Any solution found here? I just bought a Sonos One, added Deezer to Google assistant and to Sonos.
I can play Deezer on the Sonos one buy the Sonos app but when I ask google to ply it it say that Deezer is not available on the speaker

It’s working okay here - is Deezer set as your default music service in the GA App - is the Sonos Skill and speaker installed in your Google Home? Ensure you don’t have more than one language set in your Google location settings and that only one Home is set in your GA App.

Also see this Sonos support document for help troubleshooting the issue:

https://support.sonos.com/s/article/3494

Well Just removed the assistant from the Sonos One and did all the process again and at the end when I add Deezer to the GA on the Sonos One it says that this service is not compatible with this product …

But at the end it worked
Thank you

@Jeyof 

Maybe it’s just a temporary local outage, but see how it goes. I’ve tested it again here (in the U.K.) and it’s all okay, but if your problems persist however, then report back. You shouldn’t be getting a ‘not compatible’ message, that’s assuming your Deezer subscription is okay of course.

Same problem here since 3 days

I've done the process 3 times and the same answer from Google assistant " Deezer IS not available on this device"

Same problem for the last 2 weeks on Roam and Port (started 2 days after I paid for Deezer annual plan!)  Have done all the troubleshooting steps mentioned above.  Since Deezer works via the Sonos app, doesn’t this mean the problem is with Google?

Perhaps it’s a regional, or local issue. I’ve just tried this and GA on Sonos Roam is working okay here still in the U.K.

It'ok with sonos app, but unavailable with voice control with google

I’m using ‘voice’ control here …and it’s working - the app screenshot is just to show it started playing my request. So it’s perhaps something local to you - maybe Google/Sonos are updating something in your locality?

Problem is still présent only on my sonos one (x3)

All other devices like arc or move are ok

I am having the same problem.  I set Deezer as the default service for GA and none of the sonos or Google mini will accept a voice request. 

Well, 25 days later the problem just vanished.  Tried giving my infamous “Hey Google, play some rolling stones”, last night, and GA complied.  I had made no modifications to any of my hw/sw components since the command was rejected just days earlier.  Tells me the problem was in the Googleverse, and they corrected the issue.  I hope the rest of you see similar results.  Happy trails to all.

Can confirm it’s working here too.  Thanks for the update papril.