Why aren't I receiving Whatsapp and Viper notifications unless I open the app?

[Windows Central Question]

Notification problem in whats app

I have problem in receiving whats app, viber notifications. Untill i do not open app, i dont receive any msg. I have Nokia lumia 535

 

[user_of_lumia]

same problem for lumia 735. Actually sometime I receive notifications when I am on wifi. But usually I did not get any. If mobile data is on then I receive everything. What could be wrong with wifi?

 

[Musaib124]

Try turning on and off battery saver. Worked for me on 730