The store order details makes use of the order number session variable that is created in the store order summary server behavior. If you are testing consecutive transactions the additional transactions will have the same order number so it will just update the order rather than create a new one. For a new order to be created you should clear the session after yours transaction, this would force a new session to be started for the additional orders and make new unique records for those.
You can do this on your checkout success page with some code like this at the bottom of the page:
if (!session_id()) session_start();