Hello. We are implementing Redeem through Google Play, but no matter what we do, we can't solve the following error occurring on Android devices.
11:57:45 - Validation Failed: Marketplace returned HTTP status code 'GetInAppPurchasesFailure', error code 'BadRequest', and error message 'Unknown error' (This error is shown on my Samsung Phone and I typed this text. There can be some typos)
Currently, our App perfectly operates Redeem on both iOS and Steam, and also, Redeem through Google Play's Legacy API works perfectly. Therefore, we don't think it's a Service Account Key issue. We have checked all settings more than ten times.
Through the Google Cloud Console, it seems that Redeem calls are not being made through Service Account on Playfab, as there are no logs related to Redeem in the logs of the Service Account we set up.
We ask for your help in resolving this issue, as the release of our next game is imminent.