Wireless headset connection issues

Is the headset wired or wireless? If the headset is wired, it could be an issue with the cable connecting the headset to the controller.

Turn off and disconnect all controllers from the Xbox 360 and disconnect the wireless headsets from the controllers.

Connect the wireless headset to the Xbox 360 using the USB cable. Turn on the wireless headset.

Sync the headset to quadrant 1 by pressing the "Connect" button on the on the Xbox 360. Then press the "Connect" button on the wireless headset for two seconds. Do not continue to press the "Connect" button on the wireless headset, as this will change the
quadrant to which it is connected. If the headset now works without the controllers attached, the problem must be with one of your controllers. If the headset still does not work, then the problem is with the headset.

Hey there. I assume you're talking about the official Xbox wireless headset. Have you tried the following?

The headset can’t connect to a specific controller

Try the following:

Unplug any wired headsets from the console.

On the wireless headset, press the connect button. Lights on the wireless headset and on the controller are lit when they are connected. If the headset connects to the wrong position on the controller, press the connect button again to switch to the next
available position.

If your headset still won’t connect, try this:

Disconnect all other accessories from the console.

Turn off all wireless controllers:

Press and hold the Guide button on the controller for three seconds.

Confirm that you want to turn off only the controller.

Press the power button on the wireless headset.

Press the connect button on the console.

Press the connect button on the wireless headset. The lights around the console power button will spin and blink once. The position that remains lit is the position of the wireless headset.

If you want to test if the wireless headset will connect to the other positions, press the connect button again. The wireless headset connects to the next position.

Are you using a 3rd party wireless headset when playing a game?

"Third-party wireless headsets can cause active interference because they broadcast on the same frequency as wireless routers. To identify if the headset is causing the issue, disconnect the power from the base station of the wireless headset, then
check to see if this clears up the connection problem you were experiencing."

Before you go down the route of a Complete Factory reset I would try a wired connection to your router.

When connecting a wireless headset and a wired controller, connect the controller first, then the headset. The issue you described may simply have been the headset's battery being too low after the intial use.

Please try to connect in the order described and report back.