Downloaded music into Local Files, added it to my Playlist but won't play?

[GokuBlack]

Plan

Free

Country

United Kingdom 

Device

LG Stylus 3

Operating System

Android

So some time ago I was able to play music that I added into my playlist from the local files section on my computer. I'm pretty sure that this is allowed and stuff but why is it that the music I've downloaded from the Local Files doesn't work anymore? I only download music that has never been released on Spotify and it's quite strange that when it gets to the downloaded music, it just skips it and moves on to another song. 

I just recently uninstalled it, re-installed it for the same issue to happen again, what can I do??

[Joe]

Importing local files on free mobile is no longer supported. You can read more here.

[GokuBlack]

aww but why though