Blower running but no air movement

Hello, I am hoping to tap into your collective experiences for an issue I am having with my 2001 S8. I am able to run the blower motor from low to high and everything sounds normal. The A/C is also working fine. However, a short while after starting the car, you can hear the tone of the air change and no more air movement from any of the vents. I have inspected the fresh air intake valve under the hood and it appears to be opening and closing just fine. It seems like there might be a second vent control that is shutting off the air from the blower to the vents. What's weird is I can press the Econ button and then I get air movement, just no A/C. Any insight you can provide would be greatly appreciated.



Thanks!