Resolved - Motors not receiving commands from either easel or UGS

Actually, grbl is the code that is running on the Arduino. What you are attempting to do is to communicate with the Arduino (running grbl) from your USB port on the computer.

If you have the Arduino IDE installed on your machine you can get a little closer to the actual hardware if you try testing with the Arduino IDE serial monitor.

Take a look at this thread to see if you want to try that: