The XO Four Stealth includes a Headset Audio Controller (HAC) that connects to the Xbox One Controller to send game and chat audio to the headset. Please try the following if you are having difficulty plugging the Headset Audio Controller into your Xbox One Controller.
We also have a XO One (Headset Audio Controller) Setup Video that demonstrates how to plug in the Ear Force Audio Controller properly:
Note: The video below also applies to the XO Four Stealth.
If you are still having an issue plugging the adapter into the controller, please contact our Support Team here: Turtle Beach Support Form