My PC shuts down when gaming.

I have my pc for about a year now without any problems. Recently it just shuts down without any signs. Screens go black pc goes full off.

When i turn it off and on with the power button on the power supply it starts just fine, like nothing happend. And i can use the pc without any issue until it gets an other stroke.

It mostly happend when gaming after 30min to 1 hour. I got it crashing on Cyberpunk 2077, Black ops 6, Titanfall 2 and more. Watch youtube or other stufs works fine.

I got a video of it happening playing Borderlands 3 on ultra graphics setting. When i play on lower settings it also happend but not as fast. The pc started just fine but phone storage was full so video cut short.

All drivers, software and bios are up to date and i did a clean instal of windows 11.

Any idee what could be the problem or what i can do to troubleshoot? Pc specs are below.

AMD Ryzen 7 7800X3D GeForce RTX 4070 EAGLE Kingston FURY Beast DDR5 DIMM EXPO 6000MHz 16GB x2 Corsair RM1000X Shift 80+ GOLD MSI MPG B650 CARBON WIFI Samsung 980 Pro M.2 SSD 2TB