Somehow I have problems with the support. Luban generates support where it should not and not where it should. What is strange is when I scale the model the supports are generated correctly.
I solved this problem by reducing the “minimum support interface surface area”.
However, I now always have a gap between the bottom of the support and the model. Every time, this gap is exactly 3 layers thick. Any idea which setting I need to change to make the support touch the model? The Support Z distance is already set to 0. Or ist this not a problem?