Autoplay Not Working

[abnelj]

I just bought a new phone (Six Mobile's ILU) and when a song ends the app isn't playing the next song unless unlock my phone and go to the app. This has made the app unusable for me because my two main uses for Spotify are to keep the tempo when I'm running (checking the app constantly so the next song will play disrupts my pace) and when I'm driving (I'd rather not crash).

Any idea why this is happening? I've checked settings on both the app and the phone and found nothing. I did a clean re-install which left me with the problem.