I have a similar problem. Have you tried turning off c-states? For me it didn't comepletely resolve the issue, but reduced the frequency a bit.
I looked in the BIOS settings but did not see where I could disable the c-states unfortunately. I did try masking all the triggers in the OS with no change.
Have you tried booting a live distro off usb to see if it’s machine or software? Maybe something that can test memory, cpu, gpu and disk - or a burn in
No I have not tried that. That’s a good idea, is there a live boot image geared toward burn-in / fault testing?
Not really. I see https://www.stresslinux.org/sl/
And besides that you could probably use whatever and just install tools from this list :
Debian operating system
Debian is a free operating system (OS) for your computer. An operating system is the set of basic programs and utilities that make your computer run. Debian provides more than a pure OS: it comes with over 59000 packages, precompiled software bundled up in a nice format for easy installation on your machine.