I have to wonder if there is an issue with the BOOST, although I’d think the Move would still show up. 

Try moving your Ethernet cable from the BOOST to a regular Sonos speaker temporarily, avoiding a surround or Sub), an report back. 

Have there been any changes recently? New neighbors? Updates to your ISP’s router? 

Have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called 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.

it's not a Boost, it's a bridge.

Thanks Bruce! 

If it’s a BRIDGE, it is even more suspect (and you’re running S1), as the BIDGE seems to have a common fault, given its age, of bad power supplies that make it hard to diagnose things. 

The Bridge would be my prime suspect too.

Consider wiring another Sonos, as above, to get working again but also consider moving to Wi-Fi instead of Sonosnet as it often performs better.

With the Bridge you are also on Sonosnet v1 which is slow and more prone to issues than v2 or Wi-Fi.