Have had Spotify and Google Home connected for about a year. Then yesterday it stopped working so I removed the Spotify sync in the Google Home app and added it again. Which worked. But - instead of having premium (familiy) - the Google Home app sais the account i Spotify Free and I got ads one i listen.
I've make sure the account is Premium and that its the right account. Restarted phone/speaker. Removed and added the account back multiple times.