Problem with app rendering on iPad display

Verify your iPad display settings:

Settings > Display & Brightness > [Display Zoom] View - set to Standard

If display zoom is already set to Standard - and the problem persists - you may need to reset your iPad settings. While a reset of your iPad settings should not cause any loss of data, as precaution, you should first ensure that you have a current iCloud or iTunes backup of your iPad:

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

When you are confident that you have a current backup, perform the settings reset:

Settings > General > Transfer or Reset iPad > Reset > Reset All Settings

Have you performed a Factory Restore?

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

For diagnostic purposes, when you complete the Factory Restore, do not restore your data/settings from your backup. Instead you should initially set-up the iPad “as new” with your AppleID - and test the iPad. If the problem clears, the issue lies in your iPad settings; if the problem remains, then you have an issue with the iPad with which you will require assistance 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

Generally, start with the least invasive - and only if necessary do you move to more drastic steps. To cite an analogy… you use the smallest hammer necessary to complete the job.

Should you choose to do so, you can either Erase All Content and Settings - wiping everything - or for the full “nuclear option”, perform a full Factory Restore - which will erase the iPad and install a fresh copy of the most recent version of iPadOS.

Perhaps update your iPad to the latest version - now iPadOS 15.6 - then test. If the problem is not resolved, please post a screenshot of the issue.