Battery Monitor Works on Pixhawk 1 but not Pixhawk 2 Cube

I’m currently having issues with getting the battery monitor to work properly on my Pixhawk 2 Cube from ProfiCNC. I thought that perhaps I had the wrong pins selected, but the Pixhawk 2 manual states they are PA2 for voltage and PA3 for current.
My test has been to take 3 battery monitors, and wire both a Pixhawk 1 and pixhawk 2 plug to it. I would plug into the pixhawk 1 first, to confirm it works correctly, and then into the pix2, where I couldn’t get it to read voltage. I have tried this with the original 3DR battery monitor/bec, the profiCNC battery monitor/bec, and an AttoPilot 180A, with a bench PSU supplying 5v. Using the same PSU I supplied 15V over the battery lines. Here is my setup.

As you can see, I flashed the latest X8 firmware onto the Pixhawk 1, and it reads the voltage just fine.

I did the same setup on the Pixhawk 2, and I the calculated voltage fluctuates all around, and does not respond to me adjusting the battery input voltage.

I’ve even went as far as saving the params from the pixhawk 1, and loading them onto the pixhawk 2, but that did not help either. If anybody has any idea how to help me get a battery monitor working with the Pixhawk 2, it would be greatly appreciated.