ECA Zone Calculation Error/How to Know if Voyage Commences in an ECA

This is an example voyage from Brownsville to Houston which should all be inside the USGC ECA zone; however, the waypoints take suggest that the ship is entering the ECA zone about 1/4 through the journey? Shouldn't this be in the ECA zone the whole time? And is there a waypoint that indicates if a voyage is starting inside an ECA or not? You could then know that if there is no EXIT waypoint that the voyage is in an ECA zone the entire time.