Air conditioning stinks

With my XJ (Bj 2005) the air conditioning stinks for a few months. Already 2x at the JagDealer disinfected and pollen filter changed – it still smells like stable, when you open the car door the next day. After a few minutes drive the smell is gone. Either the nose has become used to it, or the mief has blown out. But the next morning it starts again from the beginning. I already had several cars (other manufacturer) with air conditioning, also considerably older. But I never had this problem. Does anyone have an idea?