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I'm developing IAP using sandbox enviornment, but the API is VERY VERY VERY EXTRMELY slow.I takes about 30sec ~ 1minute to response after I make a payment on iOS, or, I am trying to restore the purchase, all I got is therestoreCompletedTransactionsFailedWithErrorcallback, and with the "Cannot connect to iTunes Store" related error.And same with the validation API: https://sandbox.itunes.apple.com/verifyReceiptOnly 1 out of 10 times will give me succesfull response, others just keep giving me timeout response.This is really annoying, I've spent my whole day of waiting the response.Anyone facing the same issue?I'm 100% sure my network works fine.