For reference, I'm on PC. I use mods, but that is not the issue. It's a tagging problem, and affects everyone. To see for yourself, make any Sim, flip their identity to the opposite gender, and dress...
Ideas
I have noticed this on some of the other meshes, too. The High School Years graduation robe puts my trans-masc sim in the femme version (no trousers) and the Discover University professor robes (with the hood) straight up gives him breasts. I am sure there are other things, as well.
