If you are experiencing functional issues subsequent to performing a system software update, try a forced-restart of your iPad - as this will often clear an isolated software issue:
- On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.
If the problem persists, set Auto Lock to Never, close the Settings App, then repeat the forced restart. After restarting, you can reset the required Auto-Lock setting.