HVAC not working properly

Can I ask which side is working correctly? It sounds like the opposite side needs a bled door actuator which is common. here are the instructions on how to change it with a guide to walk you through the steps:

https://www.2carpros.com/articles/replace-blend-door-motor

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is. Can you please shoot a quick video with your phone so we can see what's going on, that would be great. You can upload it here with your response.