Soul Calibur V - Juggling?

So I made up this combo (lol a scrub made a thing he calls a combo) with Mitsurugi (3B>B>B>236B or 236236ABK, not very original nor best but kinda effective imo). I sometimes get those 2 double slashes after launching enemy and finishing the combo but sometimes the enemy flies too far and my second B won’t reach.

What’s the deal and can I do anything to prevent it?

I dont know the conditions or anything but it might be aerial control,some combos don’t work because you can air control out of them.

Aerial Control activates after the first hit of any juggle (Unless the move is tagged to specifically hinder aerial control). This means you can’t just toss any old moves together if the opponent knows what AC is. Most players will just hold a direction so you can’t do combos like the one you listed.