No, I'm not being dogmatic. Like it or not, subjective experience is part of reality. By dismissing someone's subjective experience as a consideration you are ignoring part of reality for no good reason.

Yes, Chelsea Manning has a Y chromosome. Yes, most (but not all) people with Y chromosomes self-identify as male. So what? Why should the fact that Chelsea has a Y chromosome prevent you from referring to her as "her" if that's how she self-identifies?