Supermicro H11SSL-I code FF

Alrighty folks, on a whim I bought a AMD EPYC 7551p + H11SSL-I combo on eBay to replace my proxmox servers. Got it in, got a cooler, got it all assembled. No post. It turns on, fans spin. BMC led flashes as normal, power led solid green like normal. Plug in IPMI port and log into web interface and post code shows FF. I’ve done everything. GPU, no GPU. 1 stick of ram in different slots, same with 2 sticks. No RAM at all. Boot with CMOS battery and boot without. Unplug literally everything. Nothing. Only post code FF. So what do we say, bad Mobo from China scum? Or CPU? Every other part was known working.

Update: I’m just an idiot. You do indeed need ECC memory to boot. Got ECC memory and it booted just fine. Thanks for the help and clarification everyone!