Sorry about that. It might be also a screen graphic problem.
Try also a forced restart of your iPad:
- On an iPad with a Home button: Press and hold the top (power) 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 (power) button. Only when the Apple logo appears (it might take 20-40 seconds), release that button (ignore all other screens that might appear).
If the issue still persists, you can:
Contact Apple Support directly (they have tools to run run remote diagnostics) using this link:--> Get Support
or
Make an appointment and have your device inspected at an Apple Store or Authorized Service Provider among this list:--> Apple – Location Selector
Regards
Giulio