It’s not “gender.” It’s sex. Gender is a squishy word. It’s an interpretable word. Sex is not assigned. It just is. I think this represents the crux of the problem.
Gender is a term of grammer.
Gender is a grammatical concept. There are three genders; masculine, feminine and neutral
Sex is a biological concept. There are two sexes; male and female.
Only science-deniers believe otherwise.
XY=Male
Science
Any questions?
In my 1980’s dictionary, there were only 3 options for gender. Male, female and neutral/none. While gender can be applied to inanimate objects, like plumbing, plugs, adapters, etc, it was still quite fixed. All of the newly found genders have been invented in the past few decades. Gender as a “social construct” is quite new.