Still trying to figure this one out, have not been able to reproduce yet.
it might have happened due to how much time I spent walking in the park. i triggered 2 encounters before i transformed where someone returned some dropped money and got mugged but flashed tits to get out of it. both of them had the guys referring to the mc as female.
didn't think of the connection since it was late at night, sorry about that.
if I've done this right, this is my save where its happening in case that helps. just need to go undress.