Best answer by Keith N
Good news, everyone!
The team has developed a patch that should address the Spotify Repeating Tracks issue. If you are experiencing this, please submit a diagnostic report and reply with the seven-digit confirmation number it gives at the end. We will then flag your account for the update. Once you've been flagged for the update, check for updates on your Sonos Controller and apply the update. Afterwards, test Spotify playback and let us your results.
Anyone who has PM'd me directly should be flagged for the update.
Thank you all for your patience.