1. See IAP FAQ TN2413: My app validates its receipt with the App Store via paymentQueue:updatedTransactions: after a successful purchase. However, the returned receipt contains an empty in_app array rather than the expected products.
2. I would assume the payment order total reflects the order queue total
3. Have you seen the discussion in the SO thread? https://stackoverflow.com/questions/3139280/transaction-comes-back-after-finishtransaction-has-been-called-on-it
> All of these problems occur sporadically.
That makes it harder to troubleshoot, of course. See https://developer.apple.com/library/archive/technotes/tn2413/_index.html - Error Messages ...perhaps they can help isolate. Still no joy, consider using one of your support tickets with DTS via the Member Center to ask they look at your project. As well, consider filing bugs via the link below to see if any come back as known issues, etc.