I'm having the exact same issue as of today pal. Also not great because I'm on free, so to get it to continue playing I have to press skip, but can only do that so many times and then I'm stuck with no music
Edit: Mine is a normal Z5, not a compact (although I doubt that makes a difference)
It started with the update that came yesterday. Before that there was no issue, so something on the spotify side has changed. But I have also had issues with the controls sometimes not showing up in the lock screen.
Same Problem for me. Spotify stops after every track, does not matter if its a generated playlist, album or on shuffle etc. Spotify Settings still has "seamless playback" enabled. Did anyone solve that yet?
I can't gurantee if this will work but if you have your Spotify app linked to your sony music account, try unlinking it by deleting the "Sony Entertainment Network" account under Android settings, restart the app and see if this fixes it.