Missing some songs in my library when I look them to download them they are already saved

[Zwid]

Over night I am missing certain songs out if my library. In some cases I saved an album and only a few songs are left. When I search for them I find they are already downloaded (only gives me an option to remove) but yet when I search my library they are not found. Missing a bunch of various artist's songs and no way to figure out which ones besides having the urge to listen to one only to discover it is not in my library.