My left CTRL key works when you press it together with any other key, however keystrokes are not recognized when you press it alone. When it starts happening, %90 of the time single strokes of my left CTRL doesnt work at all. So key combinations such as CTRL + C, V, P etc all work. But in games with CTRL as a keybind, it simply doesnt work most of the time. So Witcher, MHW, DMC5 and such games that I have 600+ hrs is affected a lot by this. I wouldnt care if it was right CTRL tbh.
I went through keyboard throubleshooting, EoA options in windows, reinsalling keyboard drivers, using safe mode, rolling back Windows updates and finally doing a fresh Win10 installation to diagnose the issue. I am positive its a hardware problem. After RMA it is still present with their factory default installation as well.
I will send you a PM with some pictures&recordings in an hour if thats alright.