I purchased the MCP-Pro about 2 months ago and it has been working just fine with my PMDG NGX and the default B738 for FSX. I just upgraded to the Prosim 737 the other day, and am having some issues. Within Prosim, the GoFlight driver is selected and the settings are correct in the MCP window. The issue is that the knobs change the appropriate values in the instrument panel, but the numbers on the MCP display don't always show the correct number. In addition, I am unable to use the disconnect bar to disconnect the autopilot and am having limited success in activating different components of the autopilot (vertical speed, etc).
I have plugged the unit into my powered USB hub, and directly to my computers USB 2.0 and 1.0 slots, but nothing remedies the situation. Like I said, it works fine with the NGX and default 737. Any ideas on where I should look next?