Why doesn't the Xiaomi 15 turn off the screen when taking calls outside the main call interface?

The Xiaomi 15 is designed to prevent accidental screen turn-off during calls in gaming or other scenarios where the proximity sensor could be blocked. Normally, when the phone is held close to the ear, the proximity sensor detects your face and turns off the screen to avoid accidental touches. However, if the call is made or received outside of the main call interface (such as when you're using a third-party APP), the proximity sensor can not trigger the screen turn-off function to avoid interference during such activities. This design helps maintain screen accessibility for tasks like gaming or multitasking during a call.