gender-bender story except the gender the dude got transformed into is a non-binary one
"Oh god! I've transformed into a girlthing!?"
"What!? I've transformed from a boy into a demi-boy!"
"Huh? ... I woke up as a [static noises]!!"
Call it "Oh no! I've Reincarnated In A Game World But My Gender Is Undefined (The Glitched Gender Saga.)"
MC gets a minor ability to manipulate the fabric of reality for any value that checks against gender, but the person who coded this universe was lazy and used gender as a check value since they assumed that no one would try to change it. It lets the MC basically play with hacks except they also don't have any normal class powers so it's not an OP MC Isekai. MC's primary quest is to find a way to fix their glitch to become one gender, but then a great evil arises that their glitch power is uniquely suited to combat against (Basically if an evil god was a rogue community manager), and MC meets trans people. They realize that they are happy being Undefined and also can use their power to help other people change their system assigned gender marker. Story then pivots into protecting their ability to change genders of themselves and others and forming a community and found family and all those wonderful queer themes.
If I wanted to give it a snappier title I'd call it "Assigned Gender At (re)Birth."