In general, if it’s not part of the music, it’s one of two things. Most likely is some sort of wifi interference sending errant signals to the speakers, but much less likely, but still possible is an issue inside the speaker. To deal with that, you should 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, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

We have fiber cable so I’m not sure about what the difference would be with regular cable and fiber cable if anything at all.  We have not yet sent a diagnostics.  I’ll try doing that today.  

Not sure what difference fiber cable would have on this. We’re talking about potential interference or network issues between your speaker(s) and your router, not between the router and the outside world.