To Edit a Preset you need to press and hold the Edit button, not the 0 button.
Assigning a Program Change and editing the Preset name on the Ground Control Pro:
1. Recall the Ground Control Pro preset you want to edit.
2. Press and Hold the Edit Button until the display changes.
3. If you named the Eleven Rack as the first device in the Device Name/Channel list then it should be showing now. If not, press the Select Down button repeatedly until you see the entry for the Eleven Rack.
4. The number at the far right side of the screen is the Program Change this preset will send to the Eleven Rack. Using the smaller numbered buttons, type the Program Change number you would like this preset to send.
5. Press the Select Down Button to get to the Preset Name screen.
6. Here you can use the Data +/- buttons to change a character and the Cursor Left/Right buttons to select which character space to change.
7. Press the Edit button to save and exit Edit Mode.
That Preset 0 does nothing (I assume only in Bank 0), suggests that it is likely programmed to not send any Program Change. You can check this by doing the above steps to see if this preset has the Program Change set to "--".
Let us know what you find!