Notifications don't come through unless I open apps

[Romkuz]

Am not sure if I removed an app or disabled one, but I don't know if I have an email, unless I click on Gmail and then a few emails come through. Whatsapp.com also shows similar issues. Alert says I may have a message, but I go into WhatsApp and then wait for them to appear..
Any ideas as to what's wrong?

[Uliwooly]

@Romkuz

Do you have stamina mode enabled?

[Jake-SonyXperia]

Hi @Romkuz,

Welcome to the community,

To add to what @uliwooly has asked are you running a third-party Home screen on the device? As these can remove notifications showing on the app also.

Let us know.

[YoGem]

It can be not just stamina mode but the basic doze of Android that is stopping certain apps, you could go in settings -> battery: click on the 3 vertical dots, top right and select battery optimization. Wait the list of apps to show up, go to 2nd tab "Apps" and select one of the apps that you need the most. 

By doing this doze won't freeze the app and you should get all the notifications on time.