Yeah, that's gonna do that. The M3Us are counted as a separate (second) drag-and-drop. This is
known behavior and is expected.
I think what you're trying to do is this (correct me if I'm wrong):
You want to do keep your PC and your player in synch by using artist/album trees as described
here.
However, you want to go the extra step of having special playlists that aren't in the artist/album tree format. You want to use M3Us to do that.
That last thing doesn't work. I know, I'd like it to work, too. But it doesn't. Complete text describing the situation is
here.