why is my controller keep flashing?

Thank you for contact us! I'm Anderson, an Independent Consultant and a Microsoft user like you.

good evening

Try connecting the controller to a different USB port on the Xbox One. Sometimes a particular port may not be working properly.

Try connecting the controller to a different Xbox One console or a PC to see if the problem is with the controller or the console.

Check for any visible damage to the controller or the USB cable, such as frayed wires or bent connectors. If you see any damage, the controller or cable may need to be replaced.

Try resetting the controller. To do this, hold down the Xbox button on the controller until it turns off, then unplug the controller from the console. Wait a few seconds, then plug the controller back in and turn it on by pressing the Xbox button.

If none of these steps help, you may need to update the controller's firmware. You can do this by connecting the controller to the Xbox One with a USB cable and going to "Settings" > "Devices" > "Controllers" on the console. From there, select the controller and choose "Update" to install any available firmware updates.

I hope these suggestions help you fix the problem with your controller.

Hello!

Thanks for reaching out to us here on the forums with this situation. I understand you're having trouble with a couple of controllers staying synced to the console. Take a look at the steps listed in this support article:

Troubleshoot your Xbox One wireless controller. If those steps don't resolve the situation. Try safely powering down the console and then unplugging it from its power source completely. Leave it unplugged for about 2 minutes or so. After the time has passed
remove the batteries from the controller and connect it with a working USB cable to the console. Then use the controller itself to power up the console by holding the Xbox Guide button (light up Xbox logo). If it starts up try replacing the batteries and unplugging
the USB once you're at the home screen. Give it a try and let us know with a reply if this helped.

Try re-syncing the controller

Try pushing the sync buttons on both the controller and console, If that doesn't help try performing a hard reset EXACTLY like this. Hold the power button on the console for 8 seconds or until the power shuts down completely. Unplug the power
cord from the back of the console for 5 minutes. Plug the power cord back in and restart the console.

Ive just got my new xbox, i went to sync the controller, both lights flash, it syncs then the controller goes off, any ideas why?