Spotify taking more space than it says

[Eemilp]

Plan

Premium

Device

• Oneplus one 64gb

My Question or Issue

I have about 1500 songs saved ln spotify. When I look in spotifys settings it says that the downloaded files are about 5gb, but when k look in my phones setting spotify takes 22gb of space. What is going on here? I had the download quality on very high before when spotify changed it back to normal by itself maybe in some update. I would be fine with the music taking 22gb but if most of it is just unused data from previous downloads I'm pretty dissapointed. My spotify seems to begin downloading all of the songs again when I set the quality higher again. 

Thanks!

Eemil