I believe I have the same issue. Server has been running for 12+ months with 6.11.
I updated about 24 hours ago and after a few hours the server just dies, I have to power cycle it, this has happened twice in the last 24 hours so it seems to be 6.12 related atleast for my hardware.
Going to downgrade to 6.11 now.
dimraid-diagnostics-20230617-1657.zip