Why is my iPad frizz on on an app

If an App is unresponsive, it can be force-closed. To expose the App Switcher page, swipe-upwards from the bottom to the centre of the screen - and pause briefly before lifting your finger from the screen. You will see a small thumbnail image for each open App; simply swipe the thumbnail that corresponds with the unresponsive App off the top of the screen.

If the iPad itself is fully unresponsive to screen input, perform a force-restart:

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:

1. Press and quickly release the volume button nearest to the top button.
2. Press and quickly release the volume button farthest from the top button.
3. Press and hold the top button.
4. 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 it was me then I would try

Force restart iPad - Apple Support