I have the exact same problem. Everything works on Catalina, everything works on Big Sur as well until the first shot down (So the install is successfull, i could see the dock with the desktop). After reboot it goes black when normally the apple logo comes for a few sec.
I have this config:
Asus TUF z370 Pro Gaming
Intel Core i5-8600K 3.60GHz LGA-1151 300, Coffee Lake
Gigabyte Radeon RX 5700 XT 8GB Aorus (GV-R57XTAORUS-8GD)
M.2 Samsung 970 PRO
Intel I219V
And i use this EFI
Any suggestions? I would really appreciate it!