I've had minor troubles with that, especially doing a 2,1, 2+4 ender in SR, whiffs on females and a few others. I always have to briefly hold forward or quick dash cancelYeah it sucks. I use 11xx db3 amp, dash, 4 now on all characters. You miss only like 20 damage for a combo you can hit 10/10 times. On KB the combo is pretty hard even on males and borderline impossible so 4 is the way to go there.