Hmm. Might be a problem with converters in the mill, triticale is seen as wheat most likely... Didn't thought about messing up with contracts...
Tried to simplify the recipes in productions with this converters. Till I find a solution, try to avoid contracts that sell to productions (one solution would be to eliminate the sell station on productions, the other would mean I have to redo all the productions without converters...)
Thanks for informing me.