You’re confusing the two.
There is no proof homosexuality is biological in origin. If that were true, there would be no switching from homosexuality to heterosexuality (and vice versa).
It appears that human sexuality is very flexible, and that instead of the “I was born this way” it is “I can’t help that I feel this way”. In other words, a personality disorder.
I never stated what the origin of homosexuality is. I have no idea to be honest. I just use the old Dice Clay definition. You either do or you don’t (I cleaned it up a bit). In my own case, one look at Barbara Eden on “I Dream of Jeannie” when very young, I knew which side I wanted to be on.