Had this too. Couple of ways to solve :
-Unplug all wires (earpiece,charging cable)
-Off all wifi or data
-Close app apps
1. Turn off your phone completely, wait a couple of seconds. Hold the Power and Volume Up button Release Power button when apple logo appears BUT keep holding Volume Up
Release Volume Up button when lockscreen appears
Open Pangu app, wait a couple of seconds, press home button, swipe springboard left and right a couple times
Open Pangu app again and press the circle, wait a couple of seconds before you lock
If this doesnt work, try activating low power mode and repeat the steps
Final resort is to Delete the PP/Pangu app, reinstall it using Impactor as before, open it, and this time don't allow notifications (i didnt do this, found this on reddit)