Why do some of my songs re-download randomly?

[hps6211]

 As of recently, whenever I open up my spotify desktop app, 1 to 1000 songs (completely random) need to be re-downloaded. There is no pattern as the songs that are re-downloaded are not from the same playlists or artists. As I do not have an unlimited plan for my internet, this is a huge pain. I love using premium, but if this isn't resolved, I'll probably move to amazon music.

[keira4664]

I've had the same issue before and but I really can't answer your question. However, I've found that often happens after I update a playlist and add new songs.