Why do my notifications stop working?

[Android Central Question]

Hi. I have a P9 Lite and my notifications do not work at all. I have already tried to set them up and all and still nothing. Why does this happen ? And how to fix it?

 

[B. Diddy]

Welcome to Android Central! Are you saying that you never get notification icons in the status bar, even when you're actively using the phone? Or is this only when the phone is asleep?