Xbox One S turns off after 15 seconds without the loading screen/hard reset screen booting up

Sometimes a hard reset of the console will fix subscription issues like the one you're describing.

Just hold the Xbox button on the front of the console for 10-15 seconds until it turns off. Then turn the Xbox and your controller back on. You should see a green Xbox loading screen, if not you did not fully shut down the Xbox.

If the power reset suggestion above does not work, try a "hard reboot". Once you turn the Xbox on and it's been sitting at the green Xbox screen for more than 90 seconds or so, hold the power button down on the Xbox for 10 seconds or until it powers completely
off. Let it sit for another 30-60 seconds before turning it back on. Once the Console comes back up to the green Xbox screen, let it sit. Don't panic if it is still on this screen for more than 30 seconds, just be patient. Afterall, its a computer. Most
computers don't just power on and let you get right to messing around, they take a little while to boot up. Mine tends to stay there for one minute or more after a hard reboot. Let me know if this helps.

If your console is not on stand by it takes longer to boot up. It will show the green screen with the loading dots and then go to a black screen for a minute then show the xbox logo. Are you turning it off on the black screen before the logo appears? If
you can turn it on then quickly hold the power button on the front of the console until it turns off then unplug it for 30 seconds from the outlet then plug back in and try powering back on again. Hopefully it will be able to boot up no problem.

had the same problem with my 360 s. i turn it off and sometimes it takes 10 to 15 seconds to turn off. other times it goes back to the startup screen without turning off and back to the dashboard. rather frustrating when it happens.

Try hard resetting your xbox by holding the power button for 10 seconds while the system is turned on. Then the system will turn off. When you push the button again, it will start and display the start-up screen. This should fix the “game took too
long to load” problem.