iPad UI Lagging

If the issue persists, you might consider restoring your iPad to Factory Settings. Before doing so, ensure that you have a current iCloud or iTunes backup of your iPad - the procedure being detailed in this support page:

How to back up your iPhone, iPad, and iPod touch - Apple Support

When you are comfortable that you have a current backup of your iPad, you can proceed with the factory restore process - which will completely reset your iPad:

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

As the factory restore process completes, you’ll be prompted to restore your data and setting from your backup. You can also restore data directly from your backup manually:

Restore all content to iPad from a backup - Apple Support

If difficulties persist, you might be best advised to seek assistance directly from Apple Support. 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:

Genius Bar Reservation and Apple Support Options - Apple

If you are experiencing unexpected latency issues, begin with a forced restart of your iPad - as this will often clear an isolated software or performance issue:

• On an iPad with a Home button: Press and hold the top 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 button. When the Apple logo appears, release the button.

After ANY iOS/iPadOS upgrade/update, you should ALWAYS perform a simple hard reset/forced restart of your Apple mobile device.

For iPad models with a Home button, do a simple hard reset/forced restart of your iPad by holding down both the Home and sleep/wake/power button simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.