The AppAccountToken received by the server each time is the value of the first subscription

Our App uses storekit v1 to set applicationname to a string in UUID format, and our backend gets the same value in the appAccountToken in the apple store notification. In-app purchases of our app are auto-renewable and found in sandbox environment testing. After placing several orders in a short period of time, the appAccountToken in the notification received by our backend is the same value in UUID format. But the app sets the applicationname to be a different UUID format value each time an order is placed. What is the reason for this, is it normal?