Some dogs just don't like going anywhere else but in their own back yard. When I used to work Ch Buddy and PonchoBack, they would never go outside my yard. They would wait til we got home no matter how long the walk was. So it's normal. Put him on a chain spot until he goes. As soon as he goes, bring him in and reward him with workouts. If he doesn't go then don't work him out. Soon he'll know the routine. It takes time but just be patient with him.
Also some dogs absorb their food better than others and don't need to go as much.