Archetype Petrucci and Touch Screen Problems

I tried to work the Arch .Petr. standalone on my Microsoft Surface in tablet (touch) mode without pen or mouse. Everything worked fine exept the outer buttons in the lower left and right corners. (Prefenrence and Midi knob, Size triangles). I could press them, but no small window appeared. Strangely, the tuner and taptempo knobs worked OK. Has anyone experienced something similar or is it mor of a Win10 problem?

Thanks, Mavid