Troubleshooting random restarts

[Enjin]

I have been having this issue since I built my computer a couple weeks a go. Rather often, my computer will randomly restart when I am loading a game (doesnt always happen, but maybe 60% of the time?). I would normally say that its a PSU issue, but I have tried 2 different PSU's with the same result. Granted, both of them are used, but neither are very old. Im not sure what else could possibly be the issue. Any other opinions? I havent had a problem while benchmarking in Superposition or Heaven (used to undervolt), only in game. Since its a new computer, I have a few games: it happens in the menus of COD cold war and when starting up a game of LOL (when leaving the client to start up the loading screen for the actual game)

CPU: 5600x
GPU: TUF 3070 OC (Undervolted today hoping that having it pull less power could help if it was a PSU issue(restarts have been happening for much longer)
MB: ROG B550 I Gaming
RAM: 32GB (2x16) 3600 CL 16 GSkill Trident Z Neo (Currently have it set manually to 3200 since setting to DOCP wouldnt let me boot at all (did this today))
PSU: Corsair CX750M (other PSU I tried was the same model)

Thanks for your input

EDIT: The only other thing I can think of is the fact that I am not super confident in setting RAM timings/ speed. Both were set to default 2133 till today. Today I changed to 3200, but left the timings since I didnt know exactly what I was doing there. Could that be an issue?

EDIT2: I also just went from 16GB (2x8) 3600 CL 16 to 32GB a few days ago as well. Issue was happening on the initial 16GB too. 16GB was always set to default timings/ speed

 

[Enjin]

Other thing I was thinking for the purpose of figuring out what the problem is. Should I try running both PSU's? 1 PSU for mobo/cpu and the other running the GPU? I would imagine that even if both PSU's were a problem, they should still be able to handle such a small load, right?

If I were to run both PSU's I imagine I would just have to tie in the second green line on PSU 2 (GPU PSU) to the green line on PSU 1 (CPU/Mobo PSU) so both PSU's would start up at the same time?