I have seven Sonos speakers through the house, all with fixed ip addresses.
In the last three weeks Spotify is regularly losing connecting to all these speakers and will not identify them. They then randomly appear. When they are available... Music will regularly skip and pause or stop.
All seems fine when using the Sonos app to play.
I run my network through Unifi gear ( switch, USG and APs) and have rebooted and re-paired my Sonos and Spotify account multiple times.