Well, not fixed after all. First attempt to fill the truck allowed me to see that the sensor is indeed stuck. The gauge shows 2/3 full. At first i thought that perhaps it is slow to register or that in stopping when the pump clicked off that I had not actually filled the tank despite the twenty gallon add. So, I pulled into the next station and topped it off. It only took .6 gallons.
I am sure this is an isolated problem and that others should not see it, but it is aggravating. Dealer now wants it left for a few days. Hate doing that, but it needs to be fixed correctly.