That sure sounds (no pun intended) like a poor network connection between your speaker and the router. I’d certainly review the wifi interference FAQ. I’d also likely do a ‘network refresh’ to capture any potential duplicate IP address issues, as well as DNS issue ( the DNS wouldn’t affect AirPlay 2 or local library, but could potentially affect Sirius) by unplugging your Sonos from power (including any BRIDGE/BOOSTs you may have not mentioned) and while the Sonos is unplugged, reboot your router. Give the router a minute or two to recover, then plug back in your Sonos, wait a couple of minutes, and test.
If these don’t resolve your issues, I would 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 Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.
I did a quick search on the web, this link should answer your questions.