This sounds like the typical blend door actuator has failed, it can be accompanied by a ticking noise that lasts a minute or so as well. Here are the instructions on how to fix it in the diagrams below. What happens is the plastic gears inside the actuator strip out. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.
Images (Click to enlarge)
Friday, May 27th, 2022 AT 2:47 PM