For the past 2 or 3 months I've had increasing difficulties with my Sonos system. My music share on my Windows 10 computer, which had worked reliably for years, is no longer working with Sonos (“can’t browse” error.) I have trouble playing music from my mobile device (“the connection was lost”,) which was not an issue before. When I try to add music from Google Play Music or Spotify, I get error 402 messages and have to try 3-5 times to get the music actually loaded to my queue.
The firewall is configured properly on my Windows 10 computer and nothing has changed with my mobile device or home network.