VirtuaPin board - map coin button

I am in the wiring up buttons phase of my vpin build and I can't figure out how to map the coin button to my VirtuaPin controller.

Windows and the VirtuaPin Controller software show the button as #12. In VPX, I've assigned button 12 as the Coin button.

Start up a table, and hitting the button does nothing. Hitting 3-6 on the keyboard inserts credits, but not the controller button.

What am I missing?