Multiple GPU support does not work on the Crosshair VIII Extreme with Windows 11.

[Huskynarr]

My PC Specs:

Mainboard	Asus Crosshair VIII Extreme
CPU	Ryzen 7 - 5950X
RAM	G.Skill Trident Z 3200 Mhz
1. Graphiccard	RTX 3080 Ti Hybrid
2. Graphiccard	RTX 3080 Ti FTW 3
3. Graphiccard	eGPU AORUS Gaming Box (RTX 2070)

In a freshly installed Windows I have two problems.

This i have already done:
- BIOS Update
- BIOS reset
- Windows Update
- Driver complete reinstalled with DDU

Problem 1:
A second graphics card is not recognized in the 2nd PCIe slot. But using a riser on the PCI slot, the card is recognized and usable.

Are there certain BIOS settings that I may be doing wrong?

Problem 2:
The eGPU via Thunderbolt 4 is recognized, but error code 12 appears in the device manager.

[SmokeyKilla]

I had the same issue with a case that came with thunderbolt 4, however the cable shipped with the case was thunderbolt 3, make sure you are using a thunderbolt 4 cable and not a thunderbolt 3 cable.

[Huskynarr]

Have buy this Anker Thunderbolt 4 cable. But it doesnt work.