Drove 1,250 miles from new, dash says DEF 900 miles. I kept going (Highway) 150 miles later at fuel stop dash said DEF 325 miles left? I add 2.5G (shouldn’t need any at this mileage) drive another 200 miles, next gas stop dash info tells me 126 miles left? Graphic shows full? I ignore, get 100 more miles and dash turns RED and says DEF LOW! I pull over read the manual says will go to limp (5 mph) if not refilled) go to add another 2.5G and at 2G it blows out of the filler FULL??? Dealer says it’s fine no issue!! $70k and I can’t trust the dealer or the truck, never GMC again