Hello, I have problem to disable CPU graphics in BIOS.
I have this PC:
motherboard: ASUS PRIME-H370-A
proc: Intel i5-8400 (with GPU: Intel® UHD Graphics 630)
RAM 2x 8GB DDR4
GPU: MSI GTX 660 (NVIDIA)
2 LCD: EIZO 24" + DELL 24"

Until now I used Nvidia GPU for sw acceleration (photo editing etc) only, both LCDs were connected to on-board DVI/HDMI. And all worked.

I want to change it to use Nvidia GPU for both LCD now.
But if I tried to change setting in BIOS: Primary Display: CPU graphics -> PCIe , I saved changes in BIOS, but after reboot LCD are blank (going to power safe) and USB keyboard seems not working (NumLock doesn't work), and in BIOS: Primary Display is CPU graphics again.
I updated BIOS to the latest: 1901 (2020/04/07) - but no help.

Please what I'm doing wrong? Is it a bug?
Is it possible to have both LCDs on the PCI GPU?

Currently I have 1 LCD connected to on-board (i.e. CPU Intel GPU) and 1 LCD to Nvidia GTX 660.
But I want to change it.