ℹCannot Get the success PurchaseResult from SwiftyStoreKit only after several times in production environment

### Platform

- iOS

### In app purchase type

- Auto-Renewable Subscription

### Environment

- Production

### Version
ℹ 0.14.2

## Report

### Issue summary
ℹIn production environment, I don't get the success PurchaseResult from SwiftyStoreKit after subscribe success. (But Apple alert subscribe success). Only after I try for several times can I get success result from SwiftyStoreKit. This error only happens in production environment. When in sandbox environment, everything works fine.

### What did you expect to happen
ℹGet the success PurchaseResult from SwiftyStoreKit.

### What happened instead
ℹCannot Get the success PurchaseResult from SwiftyStoreKit.

```
func alertForPurchaseResult(_ result: PurchaseResult) {
switch result {
case .success(let purchase):
// NEED HELP !!! I can't go here in production environment unless I try for several times !!!
print("Purchase Success: \(purchase.productId)")
dismiss(animated: true, completion: nil)
UserPreferences.monthlyPro.value = true
SVProgressHUD.show(withStatus: NSLocalizedString("ProSuccess",comment:""))
case .error(let error):
var errorTitle = ""
var errorMessage = ""
```

Start with the reported alertForPurchaseResult callback and its PurchaseResult handling in the application code. Compare the production auto-renewable subscription flow with the sandbox flow, and verify that a successful Apple purchase reaches the .success case; the issue does not name framework files or tests.

Written by the indexing model from the issue text.