I just checked the specs on your mobo. Try running x8/x4 if that’s an option. Looks like 2nd 3.0 slot is ran from the z590 chipset. I’m not 100% sure, but I would try this.
Intel® 11th & 10th Gen Processors*
1 x PCIe 4.0/3.0 x16 slot
- Intel® 11th Gen processors support PCIe 4.0 x16 or x8/x8 or x8/x4/x4 modes
- Intel® 10th Gen processors support PCIe 3.0 x16 or x8/x8 or x8/x4/x4 modes
> Intel® Z590 Chipset
> 1 x PCIe 3.0 x16 slot (supports x4 mode)
2 x PCIe 3.0 x1 slots