Our application uses your API service for the sending push notifications from server to iOS device across Urban Airship. I have some problems with that. When I send push, urban airship successfully receives it. I made this conclusion, because in urban airship's admin dashboard, in "Reports > Push sends" tab I see, that total number of sent pushes increases. But on iOS device this pushes can come with a delay. For example, I send push to 5 users, one user receives push immediately and other with delay in 8 hours. Sometimes we have a delay in 2 minutes or 6-8 hours and currently we can’t understand why it happens. Could you please help us to solve the issue with a push delay as without huge delay our push notification are useless?