GearVR In-App purchase error

We caught an issue in our game “Sammy in VR” for GearVR. After release our IAP has been stopped working. This IAP has very simple architecture: it just remove all ads forever after purchasing. The game developed on Unity 5.5.1p3, so we use oculus sdk for Unity. 

Error description: The purchase begins, then user enters pin code, purchase completes and user returns to the game. In the same time the game receives from Oculus answer with error code “PurchaseError: Oculus.Platform.MessageWithPurchase”. 

Moreover, we could not collect logs from the release version due to Oculus Remote Debug Tool closes the game after connection every time. That is why it is impossible to fix the issue without your advices.

Would you please help us and suggest some solutions?