As I went through world 5 I got every recipe for the Magma Core set but hadn't unlocked the fifth anvil tab, when I did get the fifth tab I was disappointed to find that I would have to farm all the recipes again.
IMO the recipes learned before unlocking the tab should be unlocked or at least there should be a big warning that you are wasting the recipe by using it early and if this is stated somewhere then I would say make this more apparent to the player because I completely missed it.
#Recipes learned before you have the corresponding anvil tab are forgotten
rich dagger
forest nexus
Recipes are not 'forgotten' and work just as you want them to. (Usually)
Are you sure you got the recipes and used them or do you think you got them because they are lit up on the enemy card? Having a recipe lit up means you found a recipe of the Anvil Tab, but not per se the one on the card -> Also if you use a recipe without having the Anvil tab unlocked it also gets completely removed from the enemy card
I can only go by your words and my experience with similar complaints. If you are 100% sure you got them then I'm sorry you experienced this bug
rich dagger
Recipes are not 'forgotten' and work just as you want them to. (Usually)
Are you...
You saying this makes me doubt that i found every single one (I was looking at the lit up recipe on the card screen for a indication) from world 5 but I 100% did find a couple of them while progressing through the world, feel free to close this post it sounds like my suggestion is how the game is intended to work thanks for the reply 
forest nexus
Those are all the Anvil Tab 5 recipes you get from the normal Enemies. Maybe you can compare and see if you got any of them unlocked 
