Question Graphics card not working after disabling CSM support and enabling custom secure boot

[odobsta]

I am trying to enable Secure Boot on my PC, however, when I disable CSM, I get a black screen whenever I boot into my BIOS. My OS is installed in UEFI mode, so being blocked by legacy BIOS isn't the issue. I need to disable CSM so I can enable Secure Boot for some applications to work in Windows 11.

I have already tried resetting the CMOS and reinstalling the battery, but in both cases when I retry the steps to disable the CSM, the same issue reappears.

Does anyone know what I can do here without a full wipe and reinstall of Windows?

Relevant System Info:
MB: ASRock b550m Pro4

• fTPM enabled
• RAM Overclocked to 3800 mHz
• CSM disabled
• Secure Boot disabled

CPU: Ryzen 5 5600
Boot Drive: Adata xpg s11 pro
GPU: ZHUIFENG(Aliexpress) RTX 3080 10 gb
Windows installed in UEFI mode
I am using hdmi, so solution from this thread won't help me.

 

[helpstar]

how did you install windows in Uefi mode? on a different system?

are the drives formatted as GPT and not MBR? use MBR2GPT.EXE /allowFullOS
if not

 

[odobsta]

how did you install windows in Uefi mode? on a different system?

are the drives formatted as GPT and not MBR? use MBR2GPT.EXE /allowFullOS
if not

1st, about windows in uefi. Actually i don't know because shop where i build my pc preinstalled it for me.
2nd, about disks in gpt. JHow to check it? When i try to use mbr2gpt it says i should use windows pe
P.S., sorry for bad english, i know it very bad