On the basis of available information, it is impossible to provide definitive comment as to the likely cause. Unless the problem recurs, you should have no immediate cause for concern.
If the problem does recur, you might be well advised to seek advice 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 - or using this link:
Official Apple Support
Alternatively, you can easily 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/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:
Genius Bar Reservation and Apple Support Options - Apple