Hi, @MaLd0n
I have the same issue, I don't know if this is the way to show my login screen, but I have to type my password 2 times with enters several times even my screen is blank,
then usually there is artefac glitch on my screen after. Then after this, my login screen showed up
I have:
AsRock B450Pro4 with 4.20 BIOS Update
Ryzen 3600
RX 5600XT
latest official opencore 0.6.0
EFI.zip