Input problems in games

[Deux Alpha]

Hello guys,
I have a Cooler Master Masterkeys Pro M and some times when I enter a game (it already happened in GTA V and PUBG, can't remember if it happened in other game as well)  the keyboard input behaves like I'm tapping the key instead of holding it.

For example, I'm holding W to walk and the character begins the animation of moving forward and then stops, over and over again.
The problem goes away if I press another key at the same time and release it afterwards.

I can't understand If this is a game optimization problem or a hardware problem, in which case keyboard or motherboard?

 

Troubleshooting I've done so far:

-Plug the keyboard into a different USB (problem continues, which leads me to believe the problem is with the keyboard);

-Unplug and re-plug the cable on the keyboard side (removable cable);
-Restart Windows
-I've also ran Radeon Overlay with CPU/GPU temperatures/usage and all that, everything seems normal.

Nothing of this worked, please help!
TIA


TL;DR: Having problems with interrupted keyboard input in games, troubleshooted some things but nothing worked! Please help!!