I just went to craft my second one of these and had 4 flippers in my inventory. I had grabbed all the materials to make a total of 4 of these curios and hit craft all...
The first one I made used all the flippers as bones and I got one out of it
It has been asked to fix this problem for this craft as well as others.
Always make sure to check what is highlighted and craft items using things that count for more than one entry in the recipe one at a time. The system works on a "last in, first out" basis for the order of picking items to craft. You can control this using extra containers or by the order you place the items into the pack/container you're crafting from.
Opinions expressed in this statement are the authors alone and in no way reflect on the game development values of the actual developers.