Push notifications don't appear when iOS is on lock screen

Hi there,


I am having a problem letting the OS show the default push notification banner while the app is running but behind the lockscreen.


Test Case:

- Open the app.

- Press on the power button.

- Send a push notification from the server.


Current Behaviour:

- The phone's screen just turns on.

- No notification banner appearing on the screen.


Expected Behaviour:

- OS Notification banner to appear on the screen.


Tested on:

iOS 9 & 10


NB. Push notifications are sent, delivered & displayed otherwise than the above test case..