Pansexuals don't like people for their gender but for their personality and aren't gender specific.
Bisexuals are gender specific and look for certain qualities in each gender.
there is also the mutation of no sexual organs therefore meaning there is //technically// no gender
however chances are said people still either have a pole or a hole so
This is why I'm afraid to publicly announce I very much dislike a headcanon that views a character that was canonically born sometime in the 1940s ans dies in 1984 as a trans man (iykyk)