Keyboard suddenly turns off on Xbox One S.

It´s like asking if you can turn off a PC with the keyboard or mouse…..common OP...

Are you using the keyboard to turn on the console, or a regular controller?

My suggestion is to try using a regular Xbox One Controller (any should do, standard, Elite Series 1 or 2) to turn on the console, launch the game, then turn off the controller, and connect the keyboard and mouse after the controller has been turned off,
you should then be prompted to select an account to use the keyboard and mouse with for the game.

Hey there!

Sorry to hear you have been having these issues with the Xbox One S turning off suddenly after turning it on.

I would advise going through the troubleshooting provided in the support article that follows to try and get this issue resolved.

Your Xbox One X, Xbox One S, or original Xbox One console won't turn on

If the issue persists after all troubleshooting has been attempted, then unfortunately you will need to have the console serviced.

I hope this helps.

The xbox has 3 usbs. 1 is used by the hard drive, 2 is used by the mouse. 3 is used by my keyboard. The keyboard has 2 usb porta one for the usb passthrough and one so it works. I got bot of them plugged in but one of them is in a charging brick
next to my xbox. It still turns off.

Take the mouse out of #2 and place the controller there, take the mouse and place in the keyboard. My controller never turns off when plugged directly to the xbox. No matter what one of the devices in your xbox must go for the controller. Make everything
else work through your pass through with the keyboard.

Problem solved.

This is the official guide to troubleshoot this issue: https://support.xbox.com/en-US/xbox-one/console/console-turns-off-unexpectedly

It is usually due to poor ventilation of the console, or a power supply issue.

Ensure nothing is blocking the ventilation holes of the console if it is overheating. If it's a power supply issue, you may need to send the console to Microsoft for repair. Do not attempt to open the Xbox console and service it yourself, as this will void
your warranty. See the link above for more troubleshooting details to figure out what exactly is causing the problem.