I wonder if anyone knows how the adblue level is measured. My adblue indicator was sitting at about half full. This being the display on the dash when cycling through the various options. I added about 8 litres of Adblue with no issues. I believe I had topped it up all the way to full however the Adblue indicator still shows half full. Now the overall capacity of the adblue tank is just over 12 Litres so I now have a bit of a mystery as to how the gauge is still only reading half full. I have driven a few miles and stopped and started the car three times but still showing half full. Its a 2022 2.8D Active Model (Scotland). Any ideas?