Oldsmobile controls for ar flow control

1993 Olds Cutlass Supreme, 81091 miles, 3.1 liter

Problem: Air flow blower operates in either AC or heat mode. When the electronic controls for air flow are changed to any new position, the air flow only comes out of the floor/windshied outlets.

Question: Why doen't the air flow change location when the controls are changed to a new position, and the button indicators show that the position has been changed?