Could be network interference, in which case I’d suggest you read the wifi interference FAQ and apply what potential solutions you find. 

Could be DNS issues between your local network and the server that this station lives on.

Could be duplicate IP address issues due to your router handing out bad IP addresses when the Sonos reboots to install new firmware on the speakers.

A quick resolution to those last two would be a simple network refresh, by unplugging all your Sonos devices from power, then rebooting your router. Give the router two minutes to finish reloading everything before plugging back in all Sonos devices. 

However, if this doesn’t resolve the issue, 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.