Why are push notifications delivered irregularly?

Question

Android

We wrote a service for push notifications on the back, set up events, connected firebase, set up push notifications in apps. While we are testing only on android, we send it from the console, the push leaves but is not delivered. Firebase is the same nonsense. They behave very strangely - they can fall in a whole bunch in half an hour, they may not be delivered at all, they may be delivered instantly. What could be the reasons?

Answer 1

Delivery of push notifications is not guaranteed in time, and in general, delivery is not guaranteed. It depends on many factors (battery charge on the device, Internet stability, service load, etc.). This is fine.