Thanks for the reply, scottjritt
The spindle body is properly grounded and thus, as Michael suggested, it seems it is just creating another circuit leg that wasn’t considered as an option in the controller software. So, the fix that I’m going to have to do is swap the probe wires and only use the plate it seems. Not really a down side, a bit more convenient in my opinion but I wanted to make sure something else wasn’t wrong before I did it.