In contrast to previous two tries, the following had terribly failed:
I carmelized sugar separately. I mixed cacao liquer and some cacao butter with non-fat milk powder (as grainy stage or dry stage) and baked in the oven for 1.5 hours. I put the temperature on 75C but assume that it was 30C higher.
I grained everything (including the sugar) in my Santha 11 - it worked well for the first couple of hours but then seize and stick to the wheels (attached).
I tasted them and it feels like milk powder and not something else.
What had happened? and why it took couple of hours? the temperature of the chocolate was no over 50C.