X670E Taichi - GPU stuck in PCIe 8x - ASRock Forums

Sounds like it is your only option now if you have broken the tab at the end of the slot Only other option rather than make things worse would

I'm rather doubtful if this is the case, that you want to put a good gpu there slot rather then the capability of the slot itself

gpu with nvme slot Just being curious do you have other device plugged into PCIe slots? No SATA devices connected only SSD in M2_1 slot?

gpu slot size I've heard of some people having this same issue running a WIFI card or other hardware in the PCIE x 1 slot just above the main PCIE x 16 slot if thats the case