We use ValidateIOSReceipt to validate purchase. All works fine in sandbox environment, but in production, we always get Client/ValidateIOSReceipt: HTTP/1.1 400 Bad Request.
We were able to get the exact call data parameters of a production user. We use those parameters to test the function, and we were able to reproduce the error message.
The parameters seem all fine. We test the payload and the receipt, and there are correct and valid. The purchase price is what we aspected, and the iso code is correct.
We have no clues to resolve this problem. All other calls are working fine without a problem and on Android, all are working.