I'm in Ireland so there is the whole mess of gender and sex used interchangeably in law. There was also a push to replace sex with gender in the healthcare setting and initially people seemed to think it was the whole "oh its just more polite" and there was still only male and female categories but this is changing allowing other categories. I have stopped opening healthcare related research surveys (sent by healthcare professionals) as they asked for gender identity rather then sex which was particularly galling when looking at female specific issues or reasons for imbalance of participation in particular fields. Colleagues were told by ethics boards that they had to switch sex to gender for their research proposals to be accepted...in healthcare.
I just tried to book my 10 year old child into an event which is for ages 8 to 12 only and it asks gender: male/female/nonbinary/prefer not to say (oddly the adult version has other instead of nb).
There is no free text box or options to put sex. These are children, its so frustrating.
Sorry just venting as even when you are actively trying to avoid thinking about gender crap it creeps in to your day.