Crafting Bug
I have the same problem and it is very annoying. Figuring out new food combinations is a lot of fun for me, but I keep getting stuck when all of the ingredients don’t show up.
Cooking is not the same as other professions mainly because it’s one of the few professions that doesn’t punish you for grinding the same item. The reason why is because when you’re leveling, you’re going to be eating one food type, so the variety is supposed to be there to let you find that one food type and then craft a lot of it, then get to the next level of it and do the same thing. It’s still a bit rough, but that’s how it’s supposed to be done.
If a food stops appearing on your discovery panel, you’ve discovered everything it has to offer.
As for Artificing, the fine material ingredients should only show up in the artificing tab if you haven’t made potions.