Additional details: I have removed and reauthorized the Spotify service. Problem still persists
Try playing another music service Everywhere, then try Spotify again.
Using the Spotify service integrated in the Sonos app I just started one of my playlists, as opposed to a Spotify offered playlist. The playlist did show in the queue as expected. Then I added two more Rooms which also worked as expected. This was with the Spotify swiped out on my iPhone. Did the same with the Spotify app open on the iPhone which also worked as expected.
Looked at the Spotify app while it was playing on Sonos. The “play to” device was my iPhone. I never use “Spotify Connect” if that makes any difference.
The only time I use Spotify is when we are eating dinner. Spotify is the “Default Service” in the Alexa app. During dinner we use Echo speakers to play my Jazz playlist.
I have read that when “Spotify Connect” is playing to a Sonos speaker the queue does not show a list of tracks. Instead there is some indication that it’s Spotify that’s playing. What users were complaining about was this indication of Spotify activity could not be cleared from the queue.
Can you describe in more detail how and what you are playing using Spotify?