Question GPU works only on x16 slot with AMD Ryzen CPU ?

[catalysed]

Hey guys. I have 2 GPUs. A 3060 and a 1660 super, and they only show up when connected to a x16 slot in the motherboard. When I use a riser, they don't get detected. Other cards work fine with the riser, so it's not a riser issue. I've tried different motherboards, different risers and even different PSU. They have the same issue. I've updated the motherboard bios and the GPU bios. Set the PCIE switch to auto, gen 1, gen 2 and gen 3. None of them work. I have other 3060s and 1660 super which work fine, but just these two cards have this issue.

Build:
AS Rock B450 with Ryzen 5 2600
MSI x399 Gaming Carbon AC with AMD Threadripper 2920x
Biostar B360 with Intel i3-9350KF

 

[Koekieezz]

Hey guys. I have 2 GPUs. A 3060 and a 1660 super, and they only show up when connected to a x16 slot in the motherboard. When I use a riser, they don't get detected. Other cards work fine with the riser, so it's not a riser issue. I've tried different motherboards, different risers and even different PSU. They have the same issue. I've updated the motherboard bios and the GPU bios. Set the PCIE switch to auto, gen 1, gen 2 and gen 3. None of them work. I have other 3060s and 1660 super which work fine, but just these two cards have this issue.

Build:
AS Rock B450 with Ryzen 5 2600
MSI x399 Gaming Carbon AC with AMD Threadripper 2920x
Biostar B360 with Intel i3-9350KF

tried to update the bios to the latest and install the latest chipset drivers?

 

[catalysed]

tried to update the bios to the latest and install the latest chipset drivers?

Yep. All bios and drivers updated.