Then I would suggest you try doing 1B:B 1B:B closer to your opponent. I don't know if there's another way. When I practice for fun: 1B:B 1B:B 44B+K BE 2143B:B it always connects. Be sure you buffer 2143B:B at the right time/very early.
Aeon's hurtbox is like a brick wall. It's pretty thin on the longitudinal axis (which helps him backstep things really well) but is laterally quite wide, which can give him trouble when stepping verticals. Because of this, certain combos won't work on him, like Pyrrha Ω's 236A → 236B.Perhaps the difficulty of connecting is related to the size and shape of the various characters' hitboxes.
For me, it's trial and error, practice and luck. I cannot say for sure if you can use the same timing as you did for the first 1B:B since I am not knowledgeable enough about buffering and am not a computer that can tell if I have been using the same timing or not when executing 2x 1B:B. I was, however, able to do 5x 1B:B (definitely not a combo XD) one time, so maybe you can use the same timing at least for the second to nth 1B:B, but that might not be relevant to your question. Anyway, it seems to become a JF if you hit B around the time the sword is supposed to be horizontal in the 1B animation.how do we do the 1B:B the second time