When I unselect the "Include unticked tracks in Mini Player indexing" option for Music, Alfred ignores the setting, and displays all tracks including unticked ones.
I tried resetting the music library by both using the button on the preferences and pressing command+r on the Alfred search. I also tried quitting and reopening the Music app, and then resetting the music library on Alfred again.
(Alfred 4.3.2 on macOS 10.15.7)