I bought a USB C to Displayport Cable 1.4 off amazon. I am trying to use it for my LG Ultrafine 5k and PC and I can’t see anything. It’s even bi-directional. How come it doesn’t work?
Which LG UltraFIne 5K display do you have? Only the newer model 27MD5KL will work with a non-Thunderbolt input. Note that the display is limited to 4K60 or maybe 5K39 when Thunderbolt is not used.
I would try a solution that includes USB so you can use the USB features of the display (audio, camera, USB ports, brightness control) such as the Belkin Charge and Sync cable.