We’ve recently learned about a push notification problem exhibited by some Android devices. This is not only affecting AEM Mobile apps, but many other apps too.
On some devices, when an app is closed, background services the app uses can be shut down based on battery usage settings. The default setting for most apps (on these devices) is to be turned off in the background, ostensibly to save battery power. Since the service watching for push notifications for that app is not running, any push sent to the device for the app will not be caught and displayed.
The issue is described more fully in these articles:
The articles go on to describe a method of working around this issue by turning the setting to off (I don’t give it a name because different manufacturers call it different things). Note, however, that some apps receive pushes even with this setting on. This could be due to a variety of factors including OS versions, hardware, and the app itself. We would suggest applying these settings only on apps for which you are expecting push notifications but are not receiving them.
As an example, for a Samsung Galaxy S8 device, here is how to disable this behavior and allow the background services to continue to run (from the second linked article):
Open up you device’s Settings, and select Apps,
Click the three dots menu in the upper right,
Choose Special Access from the menu,
Choose Optimize battery usage,
There is a dropdown menu with Apps not optimized selected (normally). Click it and choose All apps,
For the apps you wish to receive pushes immediately, turn off the switch.
For other devices the steps may be somewhat different. The feature could be referred to as any of: “app auto-start, start-up manager, auto-start manager, app optimisation, protected apps, or background app management,” or possibly something else. The articles above have some links that may help with other devices.