IAP Fail delivering the receipt after a succes po-up - ios

Question

I have 2 issues :
After purchasing a subscription I receive the "You are all set Your purchase was successful" but in the SKPaymentTransactionObserver paymentQueue:updatedTransactions: I receive the SKPaymentTransactionStateFailed state with "Cannot connect to iTunes Store" error.
Some time when the purchase is initiated i receive a Confirm Purchase pop up but also the paymentQueue:updatedTransactions: is called with fail state
NOTE: I'm testing on simulator with Network Link Conditioner ( HighLatencyDNS custom profile 500ms)
Also I have notice this issue in the networks with high DNS latency more than 0.5 sec
Add Payment to queue:
- (BOOL)internalBeginPurchaseFor:(NSString *)productId
{
if ([SKPaymentQueue canMakePayments]) {
SKProduct *product;
if ((product = self.products[productId])) {
SKPayment *payment = [SKPayment paymentWithProduct:product];
[[SKPaymentQueue defaultQueue] addTransactionObserver:self];
[[SKPaymentQueue defaultQueue] addPayment:payment];
return YES;
}
}
return NO;
}
Processing transaction state:
- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray<SKPaymentTransaction *> *)transactions
{
for (SKPaymentTransaction *transaction in transactions)
{
NSString *transactionIdentifier = transaction.transactionIdentifier;
NSString *transactionDetails = #"";
switch (transaction.transactionState) {
case SKPaymentTransactionStatePurchasing:
NSLog(#"User is purchasing");
transactionDetails = #"User purchasing";
break;
case SKPaymentTransactionStatePurchased:
NSLog(#"User purchased");
[[SKPaymentQueue defaultQueue] finishTransaction:transaction];
[self executeHandlerForTransaction:transaction andSuccessFlag:YES];
transactionDetails = #"User purchased";
break;
case SKPaymentTransactionStateFailed:
NSLog(#"failed to purchase");
[[SKPaymentQueue defaultQueue] finishTransaction:transaction];
[self executeHandlerForTransaction:transaction andSuccessFlag:NO];
transactionDetails = #"Failed to purchase";
break;
case SKPaymentTransactionStateRestored:
NSLog(#"restored transaction");
transactionDetails = #"Restored transaction";
break;
case SKPaymentTransactionStateDeferred:
NSLog(#"pending for transaction");
transactionDetails = #"Pending for transaction";
break;
}
NSString *stringData = [NSString stringWithFormat:#"%# for transaction Identifier %#",transactionDetails, transactionIdentifier];
[EventLogger logEventOfType:PURCHASE_PLAN withData:stringData andNotes:#"APIAPurchase"];
}
}
any suggestions ?