There's no such thing as "the XX chromosome" and "the XY chromosome". There are X chromosomes, and there are Y chromosomes. It's also a lot more complicated than "46XX = female, 46XY = male", even if you ignore trans people. There are 46XX male people walking around who assume they are 46XY, there are 46XY female people walking around who assume they are 46XX. There are both 47XXY male and female people, again many of whom have no idea of their unusual chromosomal configuration, and various others.

XX=female, XY=male is very simplistic, and nature is much more complicated than that.