I use zendesk integration for iOS with Zendesk iOS SDK 2.3.0.
For getting push-notification we use webhook. First of all, sometimes first notification doesn't come or do it with a big delay. Only after 2-3 messages pushes start to work correctly. As well, often pushes just stop to work. Back-end server not getting any information to webhook while support chats could be reloaded and works pretty well. Sometimes, both chat and pushes stops to work while internet connection is still alive (checked with safari and different apps).
Just let me know if I can clarify some important details
Thanks in advance