PC shuts off suddenly while gaming/under load

Computer Type: Desktop

GPU: AMD 7800xt: https://shop-ca-en.amd.com/amd-radeon-rx-7800-xt-graphics/

CPU: AMD 5800x3d

Motherboard: ASUS TUF x570 Plus WIFI

BIOS Version: 5013

RAM: Corsair Vengeance DDR4 3600 64GB

PSU: Seasonic Focus GX-750 80+ Gold

Operating System & Version: Edition Windows 11 Home 23H2 22631.2861

GPU Drivers: Adrenalin 24.6.1

Background Applications: Discord, Firefox, Wallpaper Engine

Description of Original Problem

My PC has been crashing during gaming or under load, almost identical to this post: https://www.reddit.com/r/PcBuildHelp/comments/1drfrtl/whats_wrong_with_this_pc_switches_off_when_gaming/

It will shut off randomly while playing graphically demanding games, such as Halo Infinite, Destiny 2, Outer Wilds, but has even happened in Escape the Backrooms. It has yet to happen in less intense games such as Titan Quest Anniversary or Rimworld.

Troubleshooting

I have tried numerous solutions to no avail, such as:

• Reinstalling drivers
• Rolling back drivers
• Testing memory
• Reseating/repasting CPU
• Installing new PSU (Corsair RM1000x, have since returned)
• Ensuring 2 separate cables are plugged in GPU
• Reinstalling & upgrading Windows
• Checking temps (CPU stays around 60-70 under load, GPU 70-80)
• Updating BIOS to latest version

I am able to reproduce this crash by running OCCT 3D test, and it will usually crash within 10 seconds. What puzzles me is that sometimes it will not crash even after running for 10 minutes after changing nothing. All of this has led me to believe that there might be something wrong with my GPU, memory, or mobo.

Any and all help is appreciated!