Disable Handshake. >Utilities>Mackie#. Seems to be working for the moment.
Got it. Works now. Here's what I did and thanks to Guerilla Genus above for the clue: ...don't use Act. Just Mackie Control. Set DAW on controller to Cubase. I think that's all you need to do. Controller was not stable at first but with a reboot... seems to be stable now. -All sliders/banks, knobs & banks. Pads& banks. The only thing 'not' is the circle button which I expected to arm the track for recording.