TestFlight responses inconsistent

Greetings all, I'm trying to track down the source of a problem we're having with testing IAP on iOS. Not asking anyone to debug for me right now, just trying to ascertain if this is a common Apple test server issue or if there is something wrong with my build.

IAP on TestFlight has been completed on three separate accounts across four total devices. Initially it worked as intended. After a few wipes/restore purchases, the callbacks stopped being called at all, and restore purchases would time out. The logs showed this to be because the call to apple failed, "account <private> does not support multiples"

Later (~1 day), with no change to the version, IAP worked again!

Later (same day), IAP calls were returning success in Apple's modal but not triggering callbacks. Unfortunately I didn't check logs on this one and am unable to reproduce the state that caused it.

Later (~1 day), with no change to the version, IAP worked again!

Later (same day), IAP calls were triggering a PurchaseFailureReason.Unknown

As of this morning IAP is working again.

I'm wondering if anyone has seen this behavior with TestFlight, and if so what the most common causes are? I'm unsure what the appropriate path forward is here - on the one hand, it seems to be Apple side and does not seem to be account specific, though this behavior did happen to all accounts at slightly different times (when user A started experiencing the first failures, user B was still successfully able to purchase, etc). On the other hand, I would very much like to see consistent responses to IAP before going to production.

 

We frequently hear of behavior like this in the Apple Sandbox environment. Their Release/Production does not have the issues.

 

Thanks Jeff, I appreciate it! Guess I'll submit for review and see what happens.

 

Well unfortunately this happened; can't say I'm greatly surprised. I'll keep digging, possibly try a project refresh using a newer version of unity/fresh install. At a minimum another re-import of IAP.
If anyone else has similar issues or proposed solutions I'm all ears.