i'm premium user and use the Spotify-App for android (version 18.104.22.1682 on a Samsung Galaxy S3 LTE with Cyanogenmod, Android 4.4.4).
Now i've got the following problem for a while:
Sometimes, (from my point of view) random songs from random artists and albums aren't available offline, their green arrow becomes gray and i can't listen to them untill i connect to wlan and let spotify re-download them.
Yesterday, i saved and downloaded a complete album (so i can listen to the music while biking) and a hour later, 3 or 4 of the 12 songs are gray instead of green (the whole ablum was donwloaded, i checked it).
When i connect to wlan, spotify re-downloads about 50-200 songs, every day.
Maybe related to this problem: sometimes, there seems to be a similar problem with some songs; the arrow is green, but when i play the songs, the songs don't start/play and i have to skip them by hand.
I want to go to vacation in about a week, so it would be nice, when my collection is available offline.
Thank you and best regards.