Why doesn't my Messenger & Whatsapp load messages when closed?

[Android Central Question]

I have an Infinix HOT 4 & a NOTE 4
Both are running Infinix XOS Nougat build
They are not rooted

Here's what happens:
1. Unlock phone
2. Open the Facebook Messenger/Whatsapp app
3. Unlock the app
4. The app opens
5. The app starts loading messages 1 by 1 until it reaches the latest one.
6. Sometimes though it will send a push notification instantly, but sometimes it doesn't even bother.

Note: All notifications are set to "Allow".

 

[Chris5483]

Did you turn off background data?

 

[hanan123]

what background data?

 

[Chris5483]

There's an option so your phone won't use data for that app unless it's open.