Have set all MB, CPU Boost, OCs off? Have turned off any XMP MEM profiles? Checked to make sure all BIOS, Chipset drivers are the latest..?
Have unplugged then reconnected all MB, CPU, GPU power connectors?
Completely wiping (Inc deleting partitions) and reinstalling Windows..?
Possibly make a Linux or Windows install on a spare HD or USB drive? Could see if it crashes while running a Linux kernel or seperate Win. Install..
Checked in BIOS temp page to ensure nothing is getting overly hot or any reported voltages are low..?
** Also could check in Windows admin tools, event viewer for any recorded critical error messages.
*** Are you sure that particular RAM is compatible with it..? From what I could see there was only one Patriot listed for 3600 and has no listed timings for any of them..? Make sure no XMP profiles are on, & could try just running one stick as a test?
https://download.gigabyte.com/FileList/Memory/mb_memory_b550-aorus-elite-ax_matisse_200918.pdf