Dropping speakers mean wifi problems. You could call Sonos and ask them for help.
Sonos can’t do better, they’re really not in the mix, until the signal gets to your speakers. It’s much more likely either a network issue of some type, or an issue with Spotify. Sonos uses the same “player” for all streams, so if there was something going on with Sonos, it wouldn’t be just Spotify, but pretty much every other streaming company as well.
There’s a lot of potential causes for interference , as well as DNS issues between your network and the Spotify servers, not to mention the Spotify servers themselves. 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 phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.