Question Graphic card not showing within Device Manager

[TekTao]

I have an Aorus Extreme z390 motherboard and two Aorus water-cooled 2080 Ti GPUs.

When placed in together in slot 1 and slot 2, the second GPU works.
Switching the positions of the two cards, slot 2 is the working GPU.
Using two 760's in slot 1 and slot 2, they both work.
Using two 1070's in slot 1 and slot 2, they both work.

With a fresh install of Windows 10 on version 1909, I looked into the Bios and device manager to find the card and nothing. I am unsure what is going on here as the drivers for Nvidia refuse to install without a card installed. I put in both cards and it allowed the install but still did not see a card in slot 1.

What do I do now?

 

[Ralston18]

How are you connecting the GPU's to the monitors?

Modes and Areas?

http://download.gigabyte.us/FileList/Manual/IO_GUIDE.pdf

(Do verify that I found the correct IO_GUIDE.pdf)

With two GPU cards being installed I am not at all sure if and how modes and areas may be impacted but no harm in raising the question.

 

[TekTao]

Good question but I have attempted display port and HDMI on all outputs during all trials.

Your guide.pdf is correct.