It is called Klinefelter syndrome and it only affects males. Thus their sex is male.

https://www.mayoclinic.org/diseases-conditions/klinefelter-syndrome/symptoms-causes/syc-20353949

See? Male. You could have discovered this with a simple internet search instead of choosing to believe some fairytale nonsense.

I think it's safe to say that any of these talking points that have been given you by the trans lobby are scientifically flawed. Science and observable reality just isn't their thing. Much easier just to shout down women and call us bigots, isn't it? Standard misogyny from the gender woo-woo.