You have removed the screen protector and checked. That is good. Remove any case that you may have on your iPhone and check as well. Furthermore, if none of the above works then try the following-
1) 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 then release the Side button (Can take up to 20 seconds. DO NOT release Side Button when invited to Slide Power OFF).
(3) If that does not help your phone might need service ➔ Contact Apple for support and service - Apple Support
Note that your iPhone 11 is less than a year old and is therefore covered by Apple's Limited 1YR Warranty (US) and you should take advantage of it and have this thing resolved if none of the above methods resolve the issue.
Axel F.