We feel like we're at the end of the long and treacherous process of migrating to StoreKit2. But we've hit a small snag. When testing in the sandbox environment, we've found that if we don't finish a transactions, no subsequent purchase (invoked via call to purchase or the other purchase) will produce the confirmation sheet. Is this the expected behavior? The behavior is observed on iOS26 and 18.
Our app will only attempt to finish the transaction if it successfully uploads the receipt to our API. If it fails to do so for whatever reason, the transaction is left unfinished. Whilst the user is informed about this, users will commonly try again. Our concern is that since the confirmation sheet will not be shown again, users will not know they are actually paying again - most certainly not the UX we want to have. We'd much rather have our users be fully aware when they're paying us money.
The reason we're choosing not to finish the transaction until our backend has received it and confirmed the receipt to be valid is that the only way the user can get their product is if the server side is aware of this and add more time to the users account. When finishing the transaction via finish immediately after the purchase() call, the confirmation sheet is shown every time after subsequent calls to purchase().
Again, is this the expected behavior both in the sandbox and the production environments? Are we doing something wrong or misusing the product API? We are somewhat stumped because technically, we could get the first confirmation for a product purchase, and then finish it only after an arbitrary amount of calls to purchase() have been made - the user will believe they will have paid only once, but we will receive however much money we can drain from their account - most certainly not the kind of app we want to develop.
Please advise and best regards, Emīls