@raycomp

Perhaps you could try this simpler way to see if it works or not:
Backup a working voice file (eg, English_British_.vpm) in your new Garmin device's folder \Voice and move it to other locations.
Copy SpongBob.vpm to this \Voice folder, then rename it as the removed voice file's name (eg, English_British_.vpm).
Select the voice again to see if it works.
If not working, revert back by putting back the moved voice, it would not affect the system.