Do you see the nav mesh in the editor when you press P?
You moved the NavMeshBoundsVolume with the world as well right?
Since you mention the character is large, was the size adjustment made when he broke? Or have you adjusted any layer settings. He may not be finding an appropriate nav mesh layer for his size.
Under project settings, Navigation system, does he have an agent type appropriate for his size?
Are there any navigation related logging messages when you call the move function?