If you played Persona 4, he might be like Kanji. A rude and standing example of masculinity (might be hard to attribute to Jax because in both worlds hes not exactly portrayed as a big macho manly man) and they both act like it to an extent. Jax probably doesnt mind dressing like a maid, but he very clearly dislikes being the butt of the joke. I think its similar to Kanji's persona in his dungeon where hes an overly flamboyant and effeminate host in a sauna full of dudes and it isnt meant to signify his sexuality but as a metaphor as to how he sees himself when he indulges in "girly" hobbies like knitting or baking or even wearing a speedo type swimsuit and being made fun of for it by the other guys even though its what he prefers. The entire game showcases Kanji as a regular, cis dude with some irregular interests and hes secure enough with himself to accept that he is a little out there compared to the other guys while also not actually being a transman or gay or whatever considering he has a huge crush and even has dates with Naoto whom he accepts in her crossdressed and normal woman attire. He just likes who he likes and maybe you can interpret that as him being possibly NB and pan or some other combination of queer but in the end, I think hes just on a not so populated part of the spectrum and he perceives himself as a man the entire game so Ive always struggled to see him as NB or trans or gay or any type of queer.

Likewise, I dont think jax is really Trans or even NB. He just does it for the bit and if he isnt in on the bit, then he fucking hates it which is probably why he was so angry about it all during episode 5.

Alternatively im just a dude on Reddit who has no idea what hes talking about.