By any chance do you have another character that you can use to check if it's an issue with you having 100% world completion before starting the collection/getting to this collection step? If you have other characters that might have gone there and talked with the NPC (without the intent on getting the recipes) you also should check their inventory, they might have gotten the recipe without you noticing it. Please also make sure to check the inventory of the character you already tried getting the recipe with, maybe you simply overlooked it in there . Oh and just to be sure, also check the crafting window, you have learned the recipe "accidentally" (make sure to not have the "Have Materials", "Gain Experience" and "Can Equip" checkboxes checked, but leaving everything else as is (i.e. all checkmarks that where already present and are not mentioned earlier should stay checked))