What happens when you answer the call on the speaker phone and not put the iPhone to your face? Does the call continue normally then? If it does, then the issue may be with the proximity sensor on our iPhone that senses your face when you put the iPhone to your ear. This sensor turns off the touch screen so that other buttons do not get activated while you are on the phone. If this is the case, then (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 and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF).
(2) If that does not help, then contact 👉 Official Apple Support OR you can always get your iPhone examined at the Apple Store 👉 Genius Bar Reservation and Apple Support Options or at an Authorized Service Center for further diagnosis and a resolution.
Axel F.