Sometimes the video card's metal bracket has problems with installation.
The problem might be with the bottom of the bracket or it doesn't line up properly where it's secured to the computer case.
You might be able to loosen the screws that secure the bracket to the card and reposition the bracket so that it lines up properly.
You might need to bend the bottom of the bracket a little bit.
Check to see if the video card physically installs OK in the 2nd pci-e x16 motherboard slot.
You might need to loosen the screws that secure your motherboard to the computer case first, install the card and then tighten all screws.