Please correct error: filter by performer

There seems to be an error with the performance filter in smart playlists. When I select a performer, I only get records and tracks where the performer is listed as Primary Artist, and none where the artist is listed in the Credits only. E.g., I have a smartlist for all tracks Performer = Moor Mother, which were not played in the last year. There, no tracks by Irreversible Entanglements are included. Adding Moor Mother as Primary Artist would help the cause. However, in my understanding Performer is something else then Primary. A playlist filtered by performer should include all tracks the artist is in the credits.