“Neuter” is not a gender.
In German it is.
The point is that sex is biological but gender is a construct of language. When sex is meant, let’s say sex. Gender should only be used when talking about language. Many languages recognize 3 genders. (In English, “it” is the vestigial neuter pronoun.) But I don’t know of any that recognize more than three.
Your education failed you. They probably didn’t teach high school Latin but they should have taught Junior High English.
It is. When you use the article "das" before the German word for window, "Fenster," it is considered a neuter word.
This is completely arbitrary in many languages, of course, and has nothing to do with sex.