If you do not receive any notifications at all or they arrive on the device with a long delay (e.g. only after half an hour), you can take the following steps to solve the problem:

• In the operating system under settings, check whether notifications are activated.
• In the operating system under settings, make sure that background data is not restricted.
• Remove your app from the energy-saving options.
• Uninstall or disable apps that interfere with push connections for other apps:

• So-called "task killer" apps
• Energy/power saving apps that stop apps in the background
• Apps that restrict the permissions of already installed apps
• Software firewall apps
• Installation of Push Notification Fixer, if network problems occur again and again. This free app fixes problems caused by mobile phone providers or network routers.