No Air Outta The Driver Side Vent?

Ok, not sure where to go here. Everything else in the car, climate control button wise - works, in other words whatever button I click the air goes exactly where I want it to (it better, I replaced the entire unit) and when I hit the button to get the windsheild defrosted (the last button on the right with the windsheild symbol) I get air outta the windsheild and right side but not the left top side, like where the door is. When I had everything out I hit the button and I could see the door close inside the dash like it was supposed to but it never came out the left side (drivers side), only the top and right passenger side door. What the heck?

Mine does the same thing with the front vents. I have found that if you block the air a bit on the right side, it creates backpressure and forces air out of the left side. Assuming your left vent isn’t blocked with something, try throwing a book or something similar over half of the right side vent at the windshield and see if it increases air flow on the left.