For what reason do not receive notifications in the Android application on some smartphone models?

Question

Android

The application I developed has a background process that checks if there are new records on the remote server and, if so, creates a notification. On many devices, this always works, and it doesn’t matter if the application is currently open or minimized, whether it is in memory, etc. But on some, the notification is created only when you enter the application. What could be the reason?

Answer 1

doses/standby. Starting with marshmallows, the possibilities of background components are very limited (in particular, their network activity)

Answer 2

The reason may be Doze .

Answer 3

there is a background process that checks if there are new records on the remote server and, if so, creates a notification

why not just send fcm on a new record?