A forced-restart of the iPad will often clear an isolated software issue:
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.

If the problem persists, you may need to reset your iPad settings. While the reset should not affect your locally stored data, as a precaution, ensure that you have a current iCloud or iTunes backup of your iPad.
How to back up your iPhone, iPad, and iPod touch - Apple Support
When you are ready to do so, you can reset iPad settings:
Settings > General > Transfer or Reset iPad > Reset > Reset All Settings
