You are probably on the right track that a certain area on your screen may be failing. If you have a screen protector on your iPhone then try using the keyboard by removing the screen protector. NOTE that you may not be able to re-use that screen protector.
If that does not work then Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:
- Press and quickly release Volume UP button
- Press and quickly release Volume DOWN button
- Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF).
If the above does not work, then have your iPhone examined at the Apple Store or at an Authorized Service Center for further diagnosis and a resolution.
Axel F.