I have trouble executing the charge D, U + Kick with Dictator (I have no problem with other characters Down-up charge moves)
So I experimented a bit and found out that HD remix Dictator suffers the same glitch as did ST Vega in Hyper SF2 Anniversary Edition:
Charge Down, UP + Kick doesnt work!
Charge Down, Kick, then UP is the only way.
THANK you, CAPCOM 
Uhm, are you sure? I haven’t felt any difference. Was your testing programatic?
No you are wrong sorry
I presume you mean the OP was wrong 
+1 for wrong. super ST remix wrong baby. you just need more practice. don’t worry, stay positive…
HIV positive.
I urge you guys to compare Claws Charge down up move with Dictators’.
The input window as Claw is much more forgiving!
But thanks for you guys contributions!
The charge time is probably different for each move, that might be where you ave confusion.
It is not a motion problem, I am 100% on that
I’m not going to say yes or no as to whether the bug exists, but it should be more forgiving to do down, kick, up, release kick than down, up, kick because Dictator only has 2 pre-jump frames, but you can renda cancel your cr. kick into a special move with more leeway than that.
Not only does the charge time vary for every move (the charge times being compared here are actually the same), but input longevity and accidental jump animation varies for each required button press in a special.
For ST, wall dives can be executed by pressing K in 0-2 frames after pressing up (or else he jumps). However, dictator’s head stomp and devil’s reverse require pressing K/P in 0-1 frames after pressing up. There’s very little leeway so more than likely, you’re not timing it tightly enough.