I don't believe in free will, so I suppose we have reached a stalemate. In my mind, one's religion or favorite color is no more of a choice than sexual orientation. But I understand that most people would disagree with that perspective, and trying to convince you that free will doesn't exist is beyond the scope of this discussion.

Sexual and gender identity is not changeable by people

Huh? Isn't this literally the opposite of what the LGBTQ+ current ideology is? That gender identity can change at any given second of any given day, as often as you want?

so discriminating against it is categorically wrong

No one is asking for "discrimination" against LGBTQ+ people though, they're just asking for people that don't agree with their ideology to not be harrassed, censored, and banned. Pretty hilarious when you think about it - the minority group are actively calling for "discrimination" against people that they disagree with.