SnosRap75

Hi, since owning my car for the last 18 months, I have seen the adblue warning light appear usually after approx. 2 / 3 fuel fills but since around 5 / 6 fills ago I have had no warning. As though the adblue is not being used or the alarm sensor is no longer working. The car is an audi A6 black edition 2015 2.0 diesel. Any ideas anyone...