Mines done the same. Adblue fault. Got a feeling it’s going to need replacing. Also having juddering every time I turn left and right. They changed the oil before. But looks like it’ll need a new transfer case. All this at 37k on the clock. My first Audi. Not really impressed as the car is so nice to drive and looks the part too. Got another 2 years warranty and will probably get rid after that. Are Audi’s unreliable these days?