I have a custom app installed to show carrier calculated rates to the customers on checkout, actually to show a number of selectable service points near the customers address.
I have a problem that occurs only on recurring orders for subscription apps.
On the first order, the carrier calculated is selected, but on the recurring orders, the rate is switched to another rate.
That’s a problem since the customer expects us to honour his choice, and stay on the shipping rate that was initially selected.
The subscription app developer says that the app producing the calculated rates are not compatible with subscription orders, so I’m looking for an description of what the requirements are for an app generating carrier calculated rates, to be compatible with subscription orders.