According to your Motherboard's CPU SUPPORT LIST you do need BIOS Version 3.90 or newer for the 5800X3D to be recognized and to boot up.
ASRock does have a newer version than 3.90 version 4.10 which might make it more compatible with your new CPU.
Have you checked to see if your RAM is listed for the Vemeer Processors QVL LIST for RAM: https://www.asrock.com/mb/AMD/X570%20Steel%20Legend/index.asp#MemoryVM
Or check the RAM Manufacturer's QVL List to see if it is compatible?
Try installing just one RAM Stick in your Motherboard's DIMM Slot # 2 and see if it POST or boots up?
What Motherboard Trouble LED or Digital Error Code is showing when the PC doesn't boot up?