Most frequently a result of wifi interference , causing the speakers to not have a consistent connection with your router. Since each ‘stream’ on Sonos has varying tolerances for disconnects, it may not be happening on other streams.

There are a couple of suggestions beyond the FAQ I linked above, which would address other potential causes.

Try removing your SiriusXM account from the Sonos controller, then add it back in. Try unplugging all Sonos devices from power, then reboot your router. Once the router comes back, plug back in your Sonos devices. 

If none of those work, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

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.