Thanks for the pointers. It appears after disabling "global c-states", it's stayed online through the weekend! I could not find a setting for "Power Supply Idle Control" but it seems to be working now. Regarding DRAM speed, I just left it as is for now.
I think I'm having this same issue with my B450M Pro4, R5 1400, Unraid 6.10.3 trial. Where is the "Power Supply Idle Control" setting in the bios? (I can't find it)
I setup a Ryzen 5 1400 with 32GB of RAM, 1TB NVMe and 10TB platter for Proxmox or a dedicated SeaFile server but then I came across Unraid and decided I want to try it. Any major reason to avoid running it on a Ryzen 5 1400?