Perhaps the reason it was labeled "isekai" is because the setting is already in "another world" different from this one, rather than someone being transported to another world through a summoning or a glitch in the matrix, so to speak. It's not the traditional isekai manga in that sense, but the literal translation does mean "another world." And so far, I haven't actually seen any "gender bender." There is someone lying about their gender, but "he" is heavily disguised with sunglasses, a coat, a hat, etc. I can't call that "gender bender" in any sense. It's really just a shoddy job at crossdressing. Lol
Isekai: is a genre of Japanese light novels, manga, anime and video games that revolve around a normal person from Earth being transported to, reborn or otherwise trapped in a parallel universe, fantasy world or virtual world
Set in another world is just your normal Fantasy lol
the gender bender tags tends to get labeled on any manga that has a character that either transforms into the opposite gender or dresses up and disguises as the opposite gender
I started reading this because it was in a isekai list. But it's not isekai and have a lot of gender bender.... I don't know if I will continue reading this....