My XB1 controller keeps turning off after a few seconds even with new batteries

Does it turn on if you connect the controller to the console with a USB cable. Try another controller with this console and try another console with this controller. You should be able to identify which component is not functioning correctly. Check
the battery connectors inside the battery compartment, if they are not making good contact, this may not keep the controller charged

If it is under warranty ger it replaced else purchase another one.

I have this same issue. It usually starts while I am playing Cod Ghosts extinction mode. Everything is working fine until the batteries in my controller die. After I plug the controller back into the xb1, I can hear the sound from the game through my stereo
headset after a couple seconds. However, I can't hear the other people or they can't hear me. I have tried muting and unmuting them through the game options, but that doesn't fix it.

Simply turning off the controller and turning it back on does not fix it.

Simply turning off the XB1 does not fix it.

Turning off the XB1 by holding my finger on the power button for several seconds (hard reset?) and then turning it back on does seem to fix it.

Yes, the light on the xbox one controller turns off completely. I have to keep pressing the button to turn it back on then it turns off shortly after again.

Also to add, My main xbox controller says full when I checked the batteries on it, when I removed the same batteries and put them into the new controller it says Medium.

After much experiment it turns out my Xbox isn't responding to any of my controllers and I tested them on a different Xbox and it still work. My wireless controller can turn the Xbox on but the controller immediately turns itself off in seconds dispite being full charged or even with new battery.

Edit- I managed to fix the problem, had to turn off xbox and unplug power cable for a good bit. Thank for your support.