It would help if all sensible people would use the word SEX instead of the word GENDER, unless the subject is grammar.
I was thinking the same thing. Sex is biological and binomial: male/female. Gender deals with issues of grammar and starts with three genders: male/female/neither (he/she/it). Because grammar is an invented convention, I suppose it could expand to include other possibilities but any attempt I have seen to do so just involves confused thinking.