So I'll start by saying I have a Samsung Galaxy S4 mini.. ancient but still working great aside from Spotify.
A few issues:
I pay for premium and have access to my songs when I am offline. When I am offline, I only have acess to songs through the tab "songs" and "playlists". When I go to artists it says I have to get online to see them. THEN when I search a specific artist in the search bar, it finds all the songs I dowloaded from then and I CAN play them offline. but cannot access them how I used to- throught Artists. Finally, When i AM online, I can see all my downloaded artists but when I click on them, it takes me to their online page and NOT my downloaded songs from them.
Second, I cannot delete songs off my playlists. I have a bunch of playlists that I made - not dowloaded ones from other users and such. Normally I was able to remove them as I please. Now it acts like a downloaded playlist and I cannot remove any of the songs I add to them
I have my music stored on my SD card. Maybe that has something to do with it...?