Two basic troubleshooting steps:
Try a "forced" restart of your iPad, using these instructions:
- 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).
or, if the issue persists, something could have gone wrong during the latest update procedure.
I would try to install a fresh copy of iOS. To do this, create a full backup of your iPad (1), then restore it to factory settings (you need a computer to perform this step) and, in the end, set it up as new (2).
When done, restore data from your previously made backup (3).
Follow the instructions provided in these support articles:
(1) How to back up your iPhone, iPad, and iPod touch – Apple Support
(2) Restore your iPhone, iPad, or iPod to factory settings – Apple Support
(3) Restore your iPhone, iPad, or iPod touch from a backup
If you still get no help, contact Apple Support directly using this link:--> Get Support
Regards
Giulio