I was just in my university gym female changing rooms and a man walked in with his female friend. I don't know what this man identified as but he was definitely male He didn't use a locker, didn't change his shoes or anything, just sat and chatted to his female friend whilst she put stuff in the lockers.
I felt very very uncomfortable with this. Fortunately I wasn't getting changed but others were and it just didn't feel right with me. I felt like I couldn't complain about it because I fear I would have been called transphobic in the event that he identified as a trans women.