leave Spotify Premium for a few hours, come back and I can't advance to the next track

[Kicktoria]

I have an iPhone (4S).  If I start to listen to a playlist, and pause a song to go and do other things on my phone (like if I'm listening to it in the car and then I get to work), after a few hours when I go back to Spotify and it reloads (the three dots appear in the middle of the screen), the "next track" button is grayed out.  If I want to listen to a song after that, I have to go back to the playlist.This is something fairly new so it must've changed in the last update.  Will it ever go back? It's annoying.

(this is a playlist with thousands of songs, so it's not a matter of running out of songs. It also doesn't matter if it's saved offline or not, or if it's songs that are actually stored on my iPhone or not.)