PC Self Reboot while gaming

[Ratta7777]

Hi everyone, i wanted to ask if you would be able to help me know what is happening with my pc. i've build this computer myself, and it worked for over 6 months without any issue, but now for some reason, when i'm playing any kind of game, it just self reboots, i've even tried running cinebench with furmark on 4k at the same time, and it didn't self reboot or crashed, it only does it when i'm playing.

 

RIG:

CPU:Intel Core i7-12700k (NO OVERCLOCKED)

GPU: MSI Ventus 3X Plus OC RTX 3080 10GB LHR (NO OVERCLOCKED)
RAM: 32GB (16x2) DDR5 4800 MHZ Kingston FURY with XMP Enabled

MOBO: MSI MPG Z690 Carbon WIFI
AIO: MSI MAG CORELIQUID 360R V2 - 360mm Radiator mounted on front

PSU: MSI MPG A850GF - 850W 80 Plus Gold

OS: Windows 11 with latest update

SSD OS: Firecuda 530 Gen 4 1TB with Heatsink M.2 NVME 

SSD 1: Samsung 970 Evo Plus Gen 3 1TB M.2 NVME

SSD 2: Samsung 870 QVO 2TB SATA

Thermal Paste: Kryonaut

Case: MSI MPG Gungnir 110R

Fans: Default ARGB fans that the case and AIO had pre-installed from MSI