What can be errors when sending ios push notifications?

Question

iOS

A lot of messages do not reach the recipients.
It’s impossible to know for sure, but about 50 to 50 people come to the office. It is sent through the ruby ​​gem (houston and grocer, I tried both). If you selectively take a person and send, then he will come. I sent everything from one connection and in packs of 50. Anyway, it doesn’t come to everyone at once. Base - 3k devices.
10 come all.
3000 half does not come. The script does not throw errors.

Answer 1

Somewhere an error.