This is just a general problem: The term "USB C" doesn't mean anything other than the shape of the cable. There are various ways to transport video and/or audio

This is just a general problem: The term "USB C" doesn't mean anything other than the shape of the cable. There are various ways to transport video and/or audio over that connect and a given port on your PC may support a subset of them or none. Some thunderbolt ports can be used to connect an external GPU, for example, but even if it's connected your motherboard or bios might not support actually talking to that external GPU. On windows there is often a thunderbolt app on the system that you can open to see which TB features your built-in ports support... but if you're trying to plug into your GPU's USB-C port, now it's up to that specific hardware revision and your drivers to control what can happen there in cooperation with your PC and maybe your bios.