AlexVallat - 2016-03-16

It isn't using a filename to search for covers. If only an artist and no album is available, then it only searches for the album.

If you have beautiful filenames, though, what you can do is treat the track title as the album instead, and search for that. To do so, use file path pattern matching instead of ID3 tags, and use a pattern where the title part matches the %album% placeholder (and, of course, the artist part matches %artist%).