Having installed beta (unsupported) system software on your iPad, you should anticipate encountering unexpected issues and bugs.
If your iPad is not operating as expected, try a forced-restart - as this 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 after performing the restart, it may be necessary to reset the iPad to factory settings:
Restore your iPhone, iPad, or iPod to factory settings - Apple Support