I had the same problem and I racked my brains looking for the error, I even thought it was the motherboard and I changed it from an Aorus B550m pro to an Asus B550-f and it didn't work for me, I've read in several forums and it seems that it is a persistent problem in AMD chips, the PCIe port only works in 3.0, not only with video cards but also with audio cards, until now there is no bios update that fixes this problem.