Touch screen not working on some letter

Hi KELLYE13,

We appreciate you reaching out to us.

We’d like to gather additional details that may help us be in a better position to assist you.

Is the issue isolated to certain apps?

If yes, let’s check for a software update and make sure that you are running the latest version of iPadOS.

While it isn't inherently assured that an update will resolve the issue, updating to the latest software version for your device can help isolate potential software issues. 

Kindly secure a backup and update.

1. How to back up your iPhone, iPad, and iPod touch
2. Update your iPhone, iPad, or iPod touch

Then, check for app updates.

You can use the article below as a reference.

How to manually update apps on your Apple device

If no, let's try the steps below.

1. "Restart your iPad.
2. Make sure that your screen is clean and free of any debris or water.
3. Disconnect any Lightning or USB-C accessories. If your screen works after removing an accessory, try using a different outlet, cable, or charger.
4. Remove any cases or screen protectors."

You can use the article below as a reference.

If the screen isn't working on your iPhone or iPad - Apple Support

Take care!