https://www.gigabyte.com/Motherboard/Z370-AORUS-ULTRA-GAMING-20-rev-10#sp
can you see the device in bios? what other device do you have? in what slot?
1 x PCI Express x16 slot, running at x16 (PCIEX16)
* For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.
1 x PCI Express x16 slot, running at x8 (PCIEX8)
* The PCIEX8 slot shares bandwidth with the PCIEX16 slot. When the PCIEX8 slot is populated, the PCIEX16 slot operates at up to x8 mode.
1 x PCI Express x16 slot, running at x4 (PCIEX4)
* The PCIEX4 slot shares bandwidth with the PCIEX1_2 and PCIEX1_3 slots. When the PCIEX1_2 or PCIEX1_3 slot is populated, the PCIEX4 slot operates at up to x1 mode.
3 x PCI Express...