Xbox one X controller loses connection when used to power on the console.

The XBox 1 X has internal power supply so I'm wondering what you mean by "power pack". Try the steps in this Troubleshoot XBox S and
X console won't power on.

You could also try connecting your controller to the console with a uSB (play and charge) cable and use the controller Nexus button to turn the console on.

When you have the controller connected to the console via a USB data cable (make sure it's a data cable, as a lot of charging cables for smartphones only have the power lines connected, but no data lines), open the Xbox accessories app, and check if there
is a firmware update available for that controller.

If the controller is up to date, remove the batteries, and connect a USB charging power supply to the USB cable, and put it into an outlet near you. Or use a power bank to power the controller just for testing purposes.

Play with the controller connected to the USB power supply or power bank. If the controller works, remove the USB cable, and insert fresh disposable batteries (rechargeable batteries "only" provide 1.2V power compared to the 1.5V power of disposable batteries,
also rechargeable batteries immediately lose power linearly, whereas disposable batteries hold their 1.5V power just before they die completely).

Does the controller still lose power and connection?

The headset should work on an Xbox One controller and Xbox Series S/X controllers.

Turn off the controller by holding the Xbox button on the controller until the controller turns off and unplug the headset.

On your console press and hold the Xbox console button until the console turns off, remove the power cord from the console, and wait 1 minute.

Plug the power cord into your console again, turn on the console with your controller, and when you see your console's dashboard connect the headset to the controller and see if that solves the problem.

Hi Kenneth,

So it seems that your controller is not staying connected to the Xbox One X when you play and has even dropped connection while connected with a USB cable. I'd be happy to help you troubleshoot the console as the radio signal may need to be reset.

First, lets
hard reset and power cycle your Xbox.

1. Turn off the Xbox One console by pressing the Xbox button on the front of the console for about 10 seconds until it shuts down completely.
   
2. Unplug the console's power cable. Wait 5 minutes.
3. Plug the console power cable back in
4. Press the Xbox button on your console to turn on the Xbox One.

Try that first and let us know the results.

XBOX ONE X the controller cannot connect to the host after each time the controller is powered on

The specific performance is, when the user uses the controller to boot, the machine may start normally, but the controller's X key has been flashing, cannot connect with the host. Unless you remove the controller's battery and put it back again.

Try reset host, replace another controller, can not solve the problem.