If you connect the device via USB to a Mac and use the Console app to view the logs, do you see any errors come up from the PassbookUIService?
I've seen this error repeatedly, in which it seems to say a 500 was returned upon submitting my provision request with the completion handler.
https://developer.apple.com/forums/thread/772879
Topic:
App & System Services
SubTopic:
Apple Pay
Tags: