Problem phenomenon:
During a call cannot open the notification center, and the phone will automatically lock the screen.
Problem causes:
When the finger is close to the top of the screen, it is sensed by the light sensor. Since it is in a call state, to prevent accidental touches, the phone will automatically turn off the screen.
Solution:
It is recommended that you avoid the light sensor location when you pull down the notification center. You can also open the notification center after going back to the homescreen.