Delay in response for sandbox environment

we are dealing with subscriptions using sandbox environment , we are depending our the backend server to tell if user is subscribed or not, but after each subscription or any action on subscription we have observed a delay in response from appstore to our backend server, which is restricting user to perform actions on the app, Is this delay expected behaviour? , is delay because we are using sandbox environment?, will it be the same in real time produtcion environment as well?

Delay in response for sandbox environment
 
 
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