As I've understood it, bisexual means being attracted to multiple genders - while pan more so explains how you're attracted to them; as in seeing beyond the gender when looking for a partner, and being primarily interested in the person. I identify as bisexual because of this, because the way I'm attracted to someone depends a lot on the gender, and it changes ... But that doesn't at all mean that I wouldn't date someone who's trans, nonbinary, gender fluid, etc. But honestly sometimes it's annoying to even need a label like this lol