How to use getkeydown like a DmC4

DmC4 key is WASD and IJKL

I can pressd (W A and I) key.
but I can’t press (S A and I) key.

hope someone can helped me thanks!

PS.I tried typing on NOTEPAD it’s not working too.

You may be suffering from Keyboard Ghosting.

Microsoft has a good explanation and demo, you should check it out, some keyboards have a different internal layout to help stop common ghosting issues.