So at first a bunch of songs I added from mobile were missing on Desktop, and it wouldn't play many of them. So I reinstalled and that seemed to work, but only 5 seconds of each song plays before it stops. I Googled this and already deleted all files in Spotify folder to let it remake them but no. And yes, I heard cleaning the Cache works but I didn't find anything about Cache in Advanced Settings.
I have Premium so it's not that I have "high quality streaming" on.