Un-valid UEFI combination for secure boot:
Workstation OS re-installed: Windows 10 LTSC 2021 and Nvidia driver: issue with black screen (workstation does not boot up).
The secure boot does not recognize this as a valid UEFI combination of OS & video board and blocks the booting.
Uncheck the secure boot: workstation boots up, and there will be no issue with display; the NVIDIA Windows 10 Pro driver works fine under Windows 10 LTSC.
On clean (new) workstation:
When installing the A4000 card:
Disable these below Power management options in BIOS setup:
Secure boot options:
After these changes the workstation boots up with Secure Boot enabled and A4000 card installed.
BIOS is reachable after restart/shutdown/power-on