If you are unable to control the air flow direction, it sounds like the mode door actuator has failed. This actuator is on the side of the HVAC box under the dash and is responsible for the air flow direction.
Here is what I recommend: Remove the actuator and while it is still connected to power, see if it moves when changing the air flow direction on the panel. If it doesn't or makes a clicking sound, replace it.
If you look below, I attached the directions from my manual for replacing the actuator. They are vague, so if you have questions or there is something I can help with, please let me know. I was able to find a picture showing the actuator. It is pic 1. Pic 2 contains the directions.
Let me know what you find.
See pics below.
Images (Click to enlarge)
Sunday, October 3rd, 2021 AT 6:20 PM