Originally Posted by
jackal
Although it could have been a temporary glitch with either UA's systems or the APN (Apple Push Notification) servers, IME, issues with notifications can also happen if your phone has tried to latch onto a wifi network that is protected by a paywall or other login screen (i.e. Boingo, etc.) that hasn't been passed/agreed to/etc. The phone can sometimes remain in a limbo state where it thinks it's connected to the Internet via wifi so it doesn't use cellular data but data actually isn't coming in through the wifi connection. Once you either manually disconnect from the network, turn wifi off, or move out of range of the access point, the phone reconnects to the Internet via mobile data and all the notifications will then stream in.
Agreed. My wife has wifi at her office, but has to login every day to actually use it. I have the same problem that I will often try to send an iMessage, it will note "delivered" because it's gone through the Apple server and to her iPad at home, but if she isn't logged in on her phone, won't get the iMesage there. Won't show up next time she connects either. So a very probable scenario.