So, I updated my BIOS to the latest version and disabled some settings, including c-states.
The memtest came back without errors on 5 passes, picture:
Also pulled new diagnostics with the array started this time, maybe this can tell anything about the problem.
I will just wait and see if its running stable now. If not I guess I have to start switching out parts?!
jarvis-diagnostics-20190103-1628.zip