I also have a Corsair HS80 headset.
The iCUE Corsair management software indicates that no connection is being made when the stock USB-C cable is oriented one way. When flipped, it only has a connection while the cable is bent. I've ruled out loose solder connections—applying pressure to the connector in various directions had no effect.
I have neither of these connection issues while using the third-party C-to-C cable I usually use for my smartphone.