I'm having the same issue, thought it might have been the mixer, I went and got a new download of the mixer from the link above, and it seems to now only be for cow feed. I'm sad,
But anyone got a work around?
Edit: I did reread the top message and the grinder came with the map. In any regard I am still having the 1 L at a time aspect and its always with the 2nd grain input.