local files wont play on iphone

[Rory1073]

Ive got spotify premium, and a few days ago I stopped being able to listen to my local files on my phone. i can still listen on my computer, and they still appear on my phone (with the download symbol next to them, and they arent greyed out) but as soon as i try to switch to listening on my phone from my computer, the song stops playing on my computer and doesnt come up on my phone.

if i try and tap the song directly on my phone, it either comes up as playing for a split second before disappearing, or nothing happens at all.

It's not my firewall, ive checked all of that. ive connected via the same network and also my phone hotspot. none of that has worked. 

i tried making a new playlist with all my local files and downloading it and that didnt work either. i tried removing my local files from my computer and re-adding them and that also yielded no results. 

help me please!