question

Hello, in my game I am using Unity IAP with PlayFab's receipt validation, but it is not working properly. I can always purchase a product without any errors, but when I try to validate the receipt from google it randomly fails with "Invalid receipt" error. Sending the same receipt immediately after the failed call, I almost always get a successful validation. I tried different versions of Unity, IAP package, PlayFab SDK but without success.

Here is my implementation:

public PurchaseProcessingResult ProcessPurchase (PurchaseEventArgs e)
    {
        Debug.Log ("Processing transaction: " + e.purchasedProduct.transactionID);
        ValidateReceipt (e.purchasedProduct);
        return PurchaseProcessingResult.Complete;
    }


    public void ValidateReceipt (Product product)
    {
        Dictionary<string, object> receiptContent = (Dictionary<string, object>)MiniJson.JsonDecode(product.receipt);
        string payload = receiptContent["Payload"].ToString ();
        decimal price = product.metadata.localizedPrice;
        string currency = product.metadata.isoCurrencyCode;
        
        Dictionary<string, object> payLoadContent = (Dictionary<string, object>)MiniJson.JsonDecode(payload);
        string json = payLoadContent["json"].ToString();
        string signature = payLoadContent["signature"].ToString();


        Debug.Log ("Validating receipt: " + payload);


        PlayFabClientAPI.ValidateGooglePlayPurchase (new ValidateGooglePlayPurchaseRequest
        {
            ReceiptJson = json,
            Signature = signature,
            PurchasePrice = (uint)(price),
            CurrencyCode = currency
        }, 
        (ValidateGooglePlayPurchaseResult result) => 
        {
            Debug.Log ("Validation success");
        }, 
        (PlayFabError error) => 
        {
            Debug.Log (error.ErrorMessage);
        });
    }