Welcome to the community and I am sorry to hear that the issue still occurs. If you have yourSpotify account linked to your Sonos app, remove your Spotify account from Sonos. Next, log out of the Spotify app on your phone. Once complete confirm you can access the correct account directly at Spotify.com, if you can, proceed with adding the service to Sonos before linking it to your Google Assistant.

HI.
Sorry but it did not help.
Still get unknown error.

What happens when you go  to Services and attempt to link your Spotify account within Google Assistant app directly?

Same problem.

I am stuck between two companies, google tells me to talk to you even that I understand the problem is with google/spotify. But I have no channel to talk to them so Sonos have to be my voice.

I created a new account and then it worked. But I have all my home plugs and washing machine and other things connected to my g-suite account and it is not possible to share my hose to a normal gmail account. I got kinda tired after that...

Google is really bad about handling this and people been asking for that functions since 2018!

But today I was kicked out of my phone and hade to log back into it and it felt like someone at google changed something with my g-suite account and now I could at least link to my Spotify account again after some struggling (I hade to link it manually, because Sonos app wanted to remember an account that i hade logged out from) 

I guess my 2 hours talking with Google them did something, or my complains at Spotify over my problems with google or at Sonos :)

But something changed and now I can at least play music using the google assistant again and I can control my house as well. But all this forced me to create another account for Spotify to use with my phone, but that I can live with.

Solved after 2 weeks of problems and like 5 hours active talking to people /forums/reported errors.
It's clearly a google problem but they cant admit it and it feels extra bad when you have a paid g-suite account and all you get is extra problems! :(

Hi,

Sorry to hear about your experience with Google, but I am glad to hear creating another Google account was able to fix the problem. I also use Google Assistant in my system and had a similar issue a while back. I wasn’t able to get it resolve besides creating another Google account as a work around so I definitely understand your issue.

Let me know if you have any other questions or concerns.