Why am I awkward around girls if I'm ace?

This may be a stupid question, but why on earth am I awkward around girls if I'm completely asexual? Like I wouldn't consider myself awkward in general and I'm good if I'm with a group or a friend or even a guy I don't know well, but if I have to do something with a girl I don't know well it suddenly gets awkward and I don't know how to behave. I think I might also be aromantic, I'm not sure but I've never felt attracted to any girl either way so it's just confusing to me. I know teen guys are like this, but I thought it was because they're attracted to girls and I'm not so what's happening?? Idk maybe all guys are just taught to treat girls differently growing up and that's why I'm like this. It's not like a big issue or anything, I'm really just curious because it weird to me.