Not 100% certain, but I’d try a simple network refresh. Unplug all your Sonos devices from power. While they are unplugged, reboot your router. Once the router comes back up, plug the Sonos devices back in, and wait a couple of minutes before testing.

However, if that doesn’t fix it, 

I would recommend that you submit a system diagnostic within 10 minutes of recreating the ‘repeating song’, and call Sonos Support to discuss it, or post the diagnostic number here for a Community Moderator to pick up.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis. 

I have the same problem.  Resetting the router doesn’t resolve the problem.  This seems to be a connection problem between the Sonos system and its ability to “talk” with Stingray.  I am hoping someone at either Sonos or Stingray fixes this as I specifically bought a paid account with Stingray to listen to it via Sonos.

So the 'Turn it off and back on again' approach it the results I expected. A bunch of rebooted devices and the same issue with playing Stingray stations. 

Hence my suggestion to submit a diagnostic, and contact Sonos directly to look at the diagnostic.