Workaround for KB5124008 causing my discrete GPU (add-in Nvidia 4070 card) to stop displaying

I just installed KB5124008 about two days ago, and I've just started having trouble with my HDMI signal. I've had to unplug my HDMI cable a few times from the GPU and plug it back in to restore video. The issue became worse until I could no longer get any signal on the monitor. I had to RDP into the PC from another device to troubleshoot. It appears that the video flipped away from my discrete Nvidia 4070 add-in card, and started displaying on the 7950X3D CPU's integrated AMD Radeons HDMI connector on the motherboard. I was able to resolve this issue by changing this registry key:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity]

"Enabled"=dword:00000000

The default was:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity]

"Enabled"=dword:00000001

After changing from "Enabled"=dword:00000001 to "Enabled"=dword:00000000 followed by a reboot, my Nvidia 4070 GPU was able to display video again without issue. I know this likely opens up some security concerns, so am hoping to find out if this is a known issue.

In my troubleshooting, I tried updating my Nvidia 4070 from version 610.88 (game ready) to 616.92 (game ready). This didn't help the issue. I reverted back to 610.88, rebooted, same issue. Changed the above registry value to "Enabled"=dword:00000000, moved the HDMI cable back to the 4070, rebooted again, and got working video again.

BIOS version considerations: My motherboard is a Gigabyte X670 AORUS ELITE AX (revision 1.2). I already had "Settings" / "IO Ports" / "Initial Display Output" set to "PCIe 1 Slot". I didn't have the option to disable the integrated graphics in my F37e BIOS, so after fixing the issue with the registry change, I upgraded my BIOS to F42d. A new option appeared that allowed me to disable the integrated graphics completely. I've currently disabled the onboard integrated graphics, but have not yet re-enabled HypervisorEnforcedCodeIntegrity by setting it back to 00000001. I going to give it a few days to see if I have any more issues before re-enabling it. I'm posting this information in case anyone else has this issue, hoping to help others, or perhaps find a better solution.