1| Please list your full system's specs inclusive of your OS.
2| You forgot to mention your audio equipment. There are some headsets that have more than one ring on the 3.5mm jack thus the inability to parse a signal to the rest of the rings otherwise possible on a standard 3.5mm jack(2 rings).
3| Have you made sure your motherboard BIOS is up to date?
4| It'd also help to check if the latest audio drivers are installed. You can try, uninstalling and reinstalling your audio drivers to rule out any issues. On the other hand you can try and connect said headset and see if the mic port at the rear of the case.
If the case has been newly purchased, you should contact NZXT/your seller and inform them of the issue. They should be kind enough to send out a replacement front panel module free of cost.