Hi @Mazzagatti
Welcome to the Sonos Community!
Your diagnostics are showing the errors, though there’s no immediately apparent cause. I presume it has to do with networking, therefore.
Please unplug your router, your Google mesh and your Sonos speakers. Once your router has been off for 30 seconds, turn it on. Once the router is online, turn on the Google mesh, and once that is online turn on Sonos and test.
If that hasn’t helped, please try connecting one speaker to the main Google node with an ethernet cable and test again a couple of minutes later.
In both cases, please additionally test sources other than Spotify - is the issue restricted to Spotify only?