Keyboard trouble

[ραμπος]

Hey guys I'm relatively new to tekken and i play on keyboard I'm doing great overall but there a lot of inputs that the game just doesn't register and i was wondering if anyone knows a fix or has experienced anything similar

Most notable cases are:

Ki charge
I cannot ki charge when I press all the attack buttons it either does nothing or it does a grab when i press them simultaneously(I know i can put it in a bind of its own but that's not the point)

Bryan taunt
I was trying to to the taunt jet upper in practice and pressing 1+3+4 does again nothing same as the ki charge

King running grab
I was messing around with kings combos and when i input grab while running it just doesn't register(I might be messing this up but i don't think so)

Does anyone have any fix?

[Backburner]

you can pin the ki charge input to one button, the same goes with taunt

[Cosmic Spirit]

Is your keyboard allows enough inputs? I know some membrane keyboards can't register more than 3 inputs at the same time.
Also could be just hard to execute these moves as a beginner. It's hard for me to use ki charge without a bind as well (I do not use keyboard though).

[ραμπος]

I know i can do that I said it but that's not the point the point is why can't i do it normally in the first place

[ραμπος]

I think it can i have no problem pressing df3+4 simultaneously to get into stance with Shaheen so i don't know why kings running grab doesn't register