I currently have a St300 (full setup), a St30, and a St20. I primarily use Spotify connect to play to my speakers and use the St app to adjust zone volumes. Ever since the most rescent app and interface update, I'm having a horrible app experience while using spotify connect. When I start playback from the spotify app via the connect feature, then migrate over to the St app, the volume seems to bounce around sporadically on the main speaker of the group. The volume will also move up and down on its own in small increments until I restart the app.
My parents also have a St 20 and 30 that I will use with spotify connect when I go over and visit and it does the same thing. It is almost unusable at this time for me. I'm not sure exactly what changed with the most rescent update, but I eagerly await a fix for this because I prefer to use the spotify app with connect rather than using the integrated spotify feature in the St app itself.