Notifications for my messages app

[Android Central Question]

All of a sudden I just stopped getting notifications for my messages app, Hangouts, and messenger. I show the notifications being on but I cant figure out why its nit notifying me. And I'm getting frustrated can someone tell me if they know how to fix it please? Thank you

 

[B. Diddy]

Welcome to Android Central! Which phone? Any power-saving modes turned on, or 3rd party battery-saver or "RAM booster" apps installed?