I don't have enough iron to make steel, so I queued up an iron order, followed by a steel order.
As you can see, the current order is the iron order, but when I queue up the steel order the next order is another iron order.
I let the game run, in order to see if it was somehow being smart in an obscure way and when I went back to check on this a few seconds later (no long enough for a dupe to come to do anything -- the errand isn't assigned -- the refinery shows the "next order" as "iron to steel", which is to my way of thinking correct.
Steps to Reproduce
This issue has not been confirmed by a developer yet.