Just for to rule it out have you tried switching USB inputs for the MPG?
I ask because I just recently got a MPG was working great and then yesterday it stopped working. I spent half the day updating windows and making sure my Lenovo was updated as well as all the drivers.
I finally switched the USB port and it's back to working.
In my case I was getting a pop up saying MPG is enabled but no MPG is detected or something along those lines. The weird thing is that the MPG was showing it was getting a signal and before I got the pop up the MPG was still showing CNC Centroid and the dro was showing up but I got no response to the hand wheel as well as the buttons.
Then after exiting and turning it off and on and unplugging it I started getting the pop up. I tried rebooting, cycled the Acorn, rewrote the wizard settings and in the end it was the USB port. Haven't looked into weather or not other USB devices work on that port yet but I will today since I'm curious what would cause it to suddenly stop working. Sorry for the long rambling reply but maybe you'll get lucky and it's just the port like mine was.
Dan