Again, choosing how you greet someone based on their sex is sexist.Again, refusing to shake someone's hand is not sexist.
Again, simple question. What is difficulties specifically mean in this case?
Im ok with choosing to greet someone based on your preferred method of greeting.
Again, why are you so hung up on what difficulties means? If they only had difficulties when answering questions from people of the opposite sex, no matter how those difficulties manifest, it's a clear sign of sexism.
So you're ok with interacting with people of the opposite sex entirely differently to how you greet people of the same sex. You're ok with sexism. Thanks for clearing that up.