Despite the odd font choice, the behavior you describe is indicative of something blocking access to the Sonos update servers. I’d be double checking for any port blocking apps, VPNs, work profiles, virus protection apps, or the like. I’d also try to temporarily wire one device directly to my router with an Ethernet cable, if possible. 

However, if none of this resolves the issue, I would call Sonos Support directly to discuss it.

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.