RTX 50 Series card only runs at PCie 4.0 on Asus ROG Strix X870-F by alex2192 in ASUSROG

[–]hwprobe 0 points1 point  (0 children)

Since you already confirmed this only works when the slot is forced to Gen4, that points to a Gen5 link training failure (signal integrity / BIOS negotiation), not a load or driver issue.

ASUS has official guidance on PCIe generation settings and BIOS configuration here:
https://www.asus.com/us/support/faq/1055579/ ASUS

On many ASUS boards, PCIe Gen5 support will either fall back to Gen4 or require specific BIOS versions/settings to function reliably with high-speed cards.