Recurring PSU (?) problem when gaming at unrestricted FPS

Troubleshooting Help: Recurring PSU (?) problem when gaming at unrestricted FPS

This is my current part list of my 3 year old PC:

PCPartPicker Part List

Type Item Price
CPU Intel Core i7-9700K 3.6 GHz 8-Core Processor $355.00 @ Amazon
CPU Cooler NZXT Kraken X62 Liquid CPU Cooler -
Motherboard MSI Z390-A PRO ATX LGA1151 Motherboard $310.00 @ Amazon
Memory Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 CL16 Memory $44.99 @ Corsair
Storage Intel 660p 1 TB M.2-2280 PCIe 3.0 X4 NVME Solid State Drive $99.95 @ Amazon
Video Card MSI GeForce RTX 2070 SUPER VENTUS GP OC GeForce RTX 2070 SUPER 8 GB Video Card -
Case Fractal Design Meshify C ATX Mid Tower Case $99.99 @ B&H
Power Supply Cooler Master V750 Gold V2 750 W 80+ Gold Certified Fully Modular ATX Power Supply -
Operating System Microsoft Windows 10 Home OEM - DVD 64-bit $129.99 @ Newegg
Prices include shipping, taxes, rebates, and discounts
Total $1039.92
Generated by PCPartPicker 2023-07-01 18:02 EDT-0400

I originally had a Corsair RM750X V2 750W PSU, but during September last year my PC started crashing when gaming. Not CTD but completely freezing (with a hard reset the only way to wake it up again) or sometimes rebooting on its own. I found out that the PSU could be the problem, so I ordered a new one (the Cooler Master in the list above) and the problem went away. I tested the RAM and it was OK, and the Windows event log didn't show anything.

Now, not even a year later, the problem is back, at least the same symptoms. I've encountered this problem in several different games. Limiting the FPS to something below what I'm able to normally reach seems to fix the issue, but I don't see this as a long term solution. Could it be that some part of the hardware crashes during large power draw from the GPU? My GPU temps are not higher than 82 C and CPU temps are low.

Now I'm wondering if I should order yet another PSU, build a new PC from scratch or if there are any settings (e.g. in BIOS) which I'm not aware of that could solve the issue.

I'd really appreciate any help.