It’s hard to tell from your description, it could be any of several things, including wifi interference or a simple IP address issue. At the least, beyond the suggestions in the linked FAQ, I’d try a network refresh, by unplugging all Sonos devices from power, then rebooting the router. Give the router a couple of minutes to come back up before plugging back in your Sonos.

If that doesn’t 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, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.