Today, I confirmed the sandbox environment for the receipt of my subscription.original_transaction_id has been changed each time the subscription is renewed.The original_transaction_id is set to the same value as the transaction_id of the renewal of the subscription.Until last week, original_transaction_id always had the first transaction_id set.Was the specification changed?Or is it a sandbox environment bug?The guidelines have the following description.This value is the same for every specific subscription. This value is useful for relating together multiple iOS 6 style transaction receipts for the same individual customer's subscription.