Question Computer hard-freeze when gaming, how do I find my problem?

Jan 2, 2021

I have previously made a thread about this but I am unable to find the source of the problem and dont know how to test my parts.

The system is the following:
8700k stock
Asus Z370-A Bios: 2401 (latest)
32GB G-skill Trident NEO
Samsung 850 EVO 500GB
6800XT using latest drivers
Fractal Design 860W Plat+

My computer hard freezes when I play games, right now I only play Warzone so I havent really tried other games. Audio gets stuck, computer doesnt respond and after a few seconds the monitors go black and I have to reboot using the start button. This started to happen when I either installed my new GPU or made a fresh windows install on my SSD which has 24TB written. Previously with my 2070 Super I could play for hours and hours, day after day without any issue - ever.

What Ive tried:
Prime95 Blend for hours and hours, no fails or warnings.
Changed my memory for new G-Skill 32GB kit and when I did this I had windows issues right of the bat. I has to repair files and after the freezes I have to reboot several times as connection to M/K is lost and then it just works.
Same issue as above happend when I OCed my CPU beyond what it could boot into Windows in, needed repairs as it couldnt read from "D:" which has never even been on my PC. Had to reinstall windows fresh to solve this, repairs didnt work.
Samsung test and SeaTools passed
Correct scores on GPU-tests and I can loop a few without any problems but Warzone is not really causing the GPU to load much anyway so I dont know if this is the source.
I upgraded my old PSU to this new one which is a month old
Did Memtest86 1 run with my old memory kit, no fails and it still happen so probably not the new G-skill kit either(?)

I have a new 3070 RTX at home to test the system with and I can buy new SSD to try it out with good return policy to rule it out but I am really losing my mind here. The issue is happening more often if I go from "game to game" instead of like closing it down after short sessions but it WILL happen again. However this kind of windows boot issues with repairs makes kinda worried that something is off.

I feel like I have kind ruled it down to either GPU, SSD or MB.

What do you think? Can I run more tests without actually buying new hardware and just test the PC with them? Many parts are still under warranty but that doesnt help if I cant show/know which part is bad.

Please help me out here.

Thank you.