After receiving your reply, I did as you did on the same recipe. With All Grain or Partial Mash selected, the First Wort addition appears as expected; but, if you choose Extract on the same Wit recipe, the mash grains are reported as steep grains (as expected) but the First Wort Hops section disappears.
My recipe behaved similarly. If I change it to Partial Mash or All Grain, the steeping grain becomes part of the mash and the First Wort Hops appear in their proper place. Returning the recipe type to Extract changes the grains to Steep Grains and the First Wort Hops disappears from the Brew Steps.
You can replicate this behavior by opening a sample extract recipe such as Tori's Honey Wheat and changing the Northern Brewer Hops to First Wort. When Brew Steps is displayed, the Northern Brewer is not there. Change the brewing method to All Grain and it shows up in the expected location.
I know that the First Wort Hop technique is typical of a post-mash process. However, I believe that this technique can be effective following grain steeping in an extract recipe(i.e. steep 1# of Caramel for 30 minutes then steep FWH for thirty minutes at the same 150+/- temperature before moving to the boil stage).
Since the FWH IBU calculation appears to calculate properly in the recipe and in the Hop Bitterness Tool I thought its failure to appear in Brew Steps might be a bug. If you considered FWH during extract brewing to be sufficiently uncommon as not to merit scarce programming resources, then it is not a bug (but might be a future feature?).
By the way, I am a trial user. Your rapid response to both of my posted comments has been consistent with my overall impression of your website and software product. I'll be moving into the owner column this week.