Precision T3500 and PCIe x16 graphics card, Windows 10 x64bit

Hello!

I have installed a new Nvidia GeForce GTX 1050 Ti graphics card in my Precision T3500 into the first PCIe x16 slot and was not able to install the drivers: the screen would go blank and the computer would just freeze in the middle of installation.

That same graphics card works just fine in the second PCIe x16 slot with all the latest drivers installed and even with some overclocking of GPU memory.

When I moved the graphics card to the first PCIe x16 slot after the successfull installation of the driver, the computer would not boot and would just start beeping. When I moved the graphics card back to the second PCIe x16 slot it worked just fine.

Why would the graphics card work fine on the second PCIe x16 slot, but not on the first PCIe x16 slot?What is the difference between these two PCIe x16 slots in Precision T3500?

Thanks!

P.S. To illustrate this: when I say first PCIe x16 slot I mean the blue one, and the second PCIe x16 slot is the black one.