screen is off when on call
while on the call my iPhone 11 screen is switching off and it's waking up again when I press the lock button a couple of times. IDK why it's happening and it is also happening in my dad's XR phone too...
iPhone 11, iOS 14
it has a proximity sensor which conserve power by disabling the screen when the phone is held up to the ear
you can read more iPhone proximity sensor problems - Apple Community
and more iphone proximity sensor - Google-