Fireball/demon flip issue

I was wondering if any other akuma players has been having the same issue as me since akuma was out. Every now and then, when i finish a combo or blockstring with a fireball i get the demon flip instead even though i am 100% sure I’ve hit the punch button, and it’s the same thing when I combo into a demon flip, i get the fireball even though i’ve hit the kick button. I have seen no other thread discussing this issue may it be here or another website.

Make sure you’re doing HCB + P for Shakunetsu and HCF + K for Demon Flip. You might be getting the wrong move because your inputs are backwards

it’s not when I do the shakunetsu, its when I do the regular fireball. I’ve checked it in training mode, i do press HP, but i get the HK demon flip 1 out of 5. And sometimes I do HCF + HK and i get a HP hadoken instead.