I had this exact problem, but managed to fix it literally 5 minutes ago. Don't know if it helps, but what I did was go to the Apple Watch app on my iPhone, go on "Dock", and added "Now Playing" to the dock, so that when I press the side button (not the home/Digital Crown button) and swipe along to "Now Playing" I can control Spotify playback, and the screen looks as described by seanfromllanelli.
Hope this works/helps!
EDIT: not sure whether or not you've fixed it, but I've just realised I basically said what seanfromllanelli said in his post, sorry!