I am looking for advice for debugging a wallet pass not updating for some customers after successfully posting an APNS notification (pass identifier as topic, no expiration, priority 10).
Is there an exhaustive list of reasons for a wallet pass not updating or a guide for making sure updates happen reliably? Are there are any guarantees made as to when the pass is updated? We noticed it is either never updating or the update happens much later for some customers. Usually toggling "Automatic Updates" in Pass Details updates the pass immediately for affected customers.
Can it be caused by an error in the implementation of the Wallet Passes Web Service? We generate passes on the fly as a response to /v1/passes/{passTypeIdentifier}/{serialNumber}. I noticed that we also sometimes receive HEAD requests to this endpoint despite the documentation only mentioning the GET method. I was previously returning a HTTP status code 405 (Method Not Allowed). I have now updated it to also respond with headers (Content-Type, Content-Disposition and Last-Modified) for the pass for HEAD requests, but I don't know if it makes a difference.
Here is a list of issues on the customer side I was thinking of:
No connection to the internet
Low power mode (does it prevent or throttle updates?)
What happens if there is an error? Does it keep trying or does it just fail silently? In the latter case it might make sense to keep sending APNS notifications until the pass is requested successfully.
I know that you can use the PassKit framework in iOS apps to update (replace) passes. Would this be more reliable than a stand-alone Wallet pass?