Why does my iPad unexpectedly shut down?
Why does my iPad unexpectedly shut down and start back up?
iPad mini 6 Wi-Fi
On the basis of available information (none), it is impossible to speculate as to the root cause.
If you continue to experience difficulties, you might be best advised to seek assistance directly from from Apple Support - and request a remote diagnostic test.
You can contact the Support Team using the Get Support link at top-right of this page. Alternatively, you can initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:
https://apps.apple.com/gb/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 test and assess your iPad: