Hi @S0undh0und, thank you for reaching out, and welcome to the Sonos community. I’d be happy to help you all here and it would be best for those having trouble submitting a diagnostic report of your system for better understanding and see what would be best for the setup. Reply to us with the confirmation number. We and the community are always here to help.

However, while Sonos engineers did write the API, it is Spotify engineers that implemented it in their own codebase, and Sonos wouldn’t have access to Spotify’s code for their app.

One of the things that I’d recommend, since there aren’t dozens of similar cases posted in the forums, is that you try deleting the Spotify app from your device, and downloading and installing a fresh copy. Frankly, I’d do the same thing with the Sonos app. When you install new copies, it will re-force a ‘handshake’ between the two systems, which might fix the issue. I’d also be tempted to reboot the router, but more as a precaution. It wouldn’t hurt to reboot whatever device you’re using, either.