When in doubt, restart
If your iPad is experiencing issues such as freezing, apps crashing, or slow running speed, then it is time to reboot the device. Restarting/rebooting your device is the number one tip for troubleshooting most problems for iOS devices.
A common misunderstanding for iOS devices is that tapping the sleep button is not restarting the device; it is simply putting the device in "power save" mode. Rebooting the device wipes the device clean and closes any open apps in the background. This will clear out the available memory used by applications and give the iPad a fresh start, which should help with issues like those listed above.
Force restart iPad (models with Face ID or with Touch ID in the top button)
If your iPad doesn’t have the Home button, do the following:
Press and quickly release the volume button nearest to the top button.
Press and quickly release the volume button farthest from the top button.
Press and hold the top button.
When the Apple logo appears, release the top button.
Force restart iPad (models with the Home button)
Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons. This may take up to 30 seconds.