I use the "save" function (represented by a tick) to add the tracks I like to my Library. In an album for instance, I will tick the specific tracks I want to show up in my Library. Say I temporarily need to save some tracks offline for a flight for instance, and download the whole album for offline play, it will then automatically check all of the tracks from that album, and when I proceed to remove said album from my phone, it will keep all the tracks checked (not remembering my previous favorites selection). Basically, downloading tracks for offline use keep messing up with my music selection.
Am I doing something wrong here or is that a bug ?