[Help] Items required to research not consuming after reasearching it

[Roger the Architect]

Hello all,

I have just startet to make a mod where I pretend to get rid of the generic "book" item and replace it with a bunch of specific books, recipes, lost notes and sketches, to make the game more challengin. (then i'll have to generate where and the probabilities to find each object but that'ts another story) Basically the idea is that if you want to learn to cook rice, you have to travel to the swamp lands for instance.

I've startet just with a single book and as you may guess i'm already stuck!

I managed both to make a new (copyed) book named "the secrets of farming; Wheat" and changed the wheat farming research to [2 wheat straw & 1 "the secrets of farming; Wheat"]

I changed the wanderer start to have this new book already in the inventory for the sake of an easy testing and I started a game with it.

The surprise is that when i research the wheat farming, it consumes the 2 wheat straw items but the "the secrets of farming; Wheat" keeps in the research table inventory. I have returned to the construction set and the cost is there and it has a value of 1.

Any one knows what I'm missing?

Many thanks in advance