we are using firebase cloud messaging for sending notification for the user. when we going though the cloud messaging report we fount that only 5% of total send message is getting received.
why is it so? and how can we make sure that maximum messages getting received.
I had the same problem as you can see here.
I found this discussion in the comments to this answer here. Turns out that subscribing to a topic in FCM is not necessarily permanent. So don't subscribe users to a topic once. Instead do it on every app start, although it is
"not technically necessary. It may depend on your use case. For example, if you want a global topic where all users are a member of, you'd have to make sure that they are subscribed to it. Putting the subscribe method when the app starts guarantees this."
In my Case this fixed it for me. Now the Notifications are received by a lot more people than before. Only the open-count is still not working for me. It is always on zero.
