Again, there's nothing leftist about transgender rights. They're human rights. It's south of the political spectrum. Not left. Not right.
I think the misconception comes about because Democrats are clearly (somewhat) more supportive of transgender people than the Republican counterpart.
I strongly disagree, we have very different definitions of "left". What appears as normal to you, appears as radical hard left to me. What appears as normal to me, appears as radical hard right to you.
Left isn't just economic policy, it is worldview lens. In this case, you are holding a
poststructuralist position, where you have deconstructed the reality of sex. Poststructuralism is a derivation of Critical Theory, which was formulated by Marx. Hard left by definition very clearly