I had to search for the M.2. area in the bios for the Asus Z390-P motherboard. I can't seem to find its settings in the "advanced" area. It only has options to enable them (there's 2) or disable them. I left them disabled for now.

I changed the PCIE link speed to Gen2, which I assume is for the four slots PCIEX1_1, PCIEX1_2, PCIEX1_3 and PCIEX1_4. I also changed the PCIEX16_1 link speed to Gen2, which I assume is for the two slots PCIEX16_1 and PCIEX16_2.

It still won't let two cards hash. I purchased a couple of M.2 to PCIE adapters today, which I'll try if I can't get things going in the meantime. I'm not sure what to do