Need help! PCI-E slot not working if I install another graphics card

Enabling or disabling PCIe Slot Network Boot pciex16 slot configuration Unfortunately that is NOT the case, the ONLY slot this Asus X670E Extreme motherboard can operate at X16 is PCIEX16_1 slot * pciex16 slot PCIE X16 Adapter - 3Uhw2Kt Single NVME slot 9:07

rtp indo slot There are four PCI-E slot on the MB The first one supports 16x and so does the third one highlighted in yellow 4