I also have noticed this same issue. I was trying to change a male aracna into a female by removing all male parts and giving him a vag and it's still showing male and having a male mate with him eventually just caused the aracna to get the homosexual trait. I am also playing 19c. Just for laughs I gave the aracna an amnesa potion and renamed him Nadia Pryce XD. I also just tried making a human female into a male and it still shows it being a female but it says her womb is streil.