I have purchased an HDMI capture card (not a name brand, one of the alphabet soup products on Amazon). It shipped with an USB B 3.0 - USB-C cable in the box. Recently I have noticed quite a lot of MJPEG artifacts in the captured video which turned out to be caused by the card switching to USB 2.0 data rates.
Turns out, the cable has an arrow and text UP molded into the USB-C plug side. Quick check in macOS System Information shows that the device is detected with different data rates depending on the plug orientation.
The device does not work with a C-to-C (SuperSpeed 20 Gbps) cable at all when plugged into my laptop directly. It does work with a cheap IKEA USB 2.0 only A-to-C cable (at 2.0 speeds obviously, since there are only 4 pins present on the A side).
What could be the possible cause of such odd speed downgrade? Is this something that a person with some soldering experience could fix, like a missing resistor/connection/pad? I have not yet attempted opening the case.