Activity time not applied to itinerary interim (O) stop for border crossing

We are trying to model a border crossing as an interim stop on a single shipment from the US to Mexico.

The requirement is:

US Pickup → Laredo Border Crossing → MX Delivery

Laredo should remain part of the same shipment. There is no pickup or delivery at Laredo; we only need a fixed dwell time of 2 hours for border/customs processing.

Current configuration:

Laredo is configured as an Interim Point on the itinerary leg.

The resulting shipment stop is correctly created with Activity = O (Other/Interim Point).

A Special Service for border crossing is assigned to the interim point.

The Special Service uses Activity Type