One thing I’d certainly try is unplugging all Sonos devices from power. Once they’re all powered down, reboot your router, and give it a couple of minutes to come back up before plugging back in your Sonos devices to power. 

This should clear any potential duplicate IP addresses, as well as forcing the Sonos devices to reload their own OS. 

Ultimately, though, your best bet would be to 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 network and Sonos system.

The challenge there, at least right now, is that they may be swamped with other calls.