Top & bottom selected when sim is wearing full outfit in CAS

When a sim (male or female, any age from infant up) is wearing a full body outfit in CAS, they have an X on top and bottom, and if you click either X, their outfit is visibly removed, but you still need to click the X on the outfit itself before you can add that same outfit back. You can switch to a different outfit though.

It doesn't happen in reverse -- if a sim has a top and bottom, the outfit category knows it's not an outfit.

This is with a new sim from the main menu, empty mods folder.