Quick bit of information, Nexus 5x running Android 8.0 with August 2017 security patch with Spotify 8.4.21.508.  I have Spotify as "Not Optimized" under battery settings and I am not running any type of "Data Saver" options.  I have also cleared cache/data, uninstalled/reinstalled the app and tried using downloaded music and streaming music.  This occurs while using bluetooth headphones, I do not have a pair of wired headphones to try with.

Now here is the issue...

1. I start playing music and all is well.
2. The phone screen goes off after 15sec and approx. 15sec later, the music stops playing in my headphones.
3.  I then turn the screen on and see in the Spotify app the timer still ticking forward as if the song is still playing.  (If I pause the song, then press play, it will repeat the same issue once the phone screen goes off again.)
4. However, if I do not touch the phone and just sit there in silence for the rest of the song, the next song will begin playing, with no input from me, the first 30sec before stopping and repeating the issue with the next song.

I have no idea what to do at this point besides just cancelling my Premium subscription and going back to Google Play Music.