I believe dock_min is your problem. Try taking it out and using the default dock_mcm instead.
Looking at the code, dock_min does nothing but a minimization of the docking pose. Since your starting pose was created by Rosetta’s relax mode, which would have minimized it before output, then it has nothing to do – it’s already minimized according to the scorefunction. That’s why you get no change.
dock_mcm is an actual docking sampling protocol (you don’t need to pass a flag for it, it’s the default).