Someone in car home is already dealing with this matter. My car is the same model and has the same problem. The inner windshield is oily after being blown by warm air. My air conditioner filter has also been changed, and it was checked in the repair shop. It's clean, but I don't know where the oil stain came from. Whether I turn on the warm air or the cold air of the air conditioner, I can't blow them off. I wipe the front windshield with warm water, then dry it and repeat. I have no solution for the time being, and I haven't found a solution.
After unremitting efforts, I found a solution. There is something wrong with the hot air tank. It will be solved if it is replaced by a warm air tank. That must be the problem. Not running!