I am legit asking for a source, I am interested and seeing if there is a problem that is recorded and should be addressed. Otherwise, I am just going to assume the claim is junk and made only to try to form some "debate." Unisex bathrooms are on the rise, the city I live in now has more unisex bathrooms than gendered ones. If these are actually causing problems, then that should be addressed.
That being said, have gendered bathrooms even stopped assaults from happening? If that is your fear, then I will tell you that gendered bathrooms have never stopped anyone. If you are claiming normal people don't care, then why should they suddenly care when there are unisex bathrooms? If people are in there to use the bathroom, then why should there be an issue? If someone is in there for other reasons, then a gendered bathroom was never going to stop them in the first place.