Try a forced-restart - as this will often clear an isolated software issue:
Force restart iPad - Apple Support
If the problem survives the restart, you may have a hardware fault that requires attention. You might be best advised to seek assistance directly from Apple Support - and request a remote diagnostic test. You can contact the Support Team using the Support link at top-right or bottom-left of this page.
Alternatively, you can initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to offer assistance:
Genius Bar Reservation and Apple Support Options - Apple