Hi all, thank you for your help!
My unraid build hasn't been the most stable, since building it last week, it has gone unresponsive twice. I'm experimenting with turning off "Aggressive Link Power Management" which might help.
But, I've been receiving these "Machine Check Error" warnings, which may be the true source of the flakes. I first noticed the warning yesterday, and then a new one popped up over night during a parity build.
(in case the mcelog data isn't included, I copied output here - https://pastebin.com/V4UzpeL3)
donatobox-diagnostics-20220730-1012.zip