It's something I don't know much on, but I can say from personal experience-
The reason I've never really felt comfortable with my birth gender is mainly cause I've always really hated my body due to low self-esteem, well it's barely existent, but as I learned more and more about different genders and that. I've been realizing how I've never really felt all too comfortable not just because of my body, but the way I've been acting and how I didn't really fit into that specific gender, and honestly realizing that I was non-binary, was probably the best thing I could do.