It seems that as my Jeep G.C. gets older that when I fill my as tank it shurs off way too soon, after the first time it does this I can easily put in 3 ro more gallons.
Is there a reason for this?
Blame the gas pump nozzle, not your car. Maybe they are just making them more sensitive these days.
some vehicles should not be filled more than 95% of capacity. almost all vehicles are that way.
Did you buy it new? How long have you had it? Did it always do this? Have you always been topping off the tank?
There are a number of possible reasons. One is the result of topping off the tank when you fill it. If you look around in the owner’s manual or the sticker on the gas filler door etc. you will likely find a warning label telling you not to do it. If so you may now know why that label is there. You can damage the system and may need a new charcoal filter.
It also could be as Steve wrote, a sensitive nozzle. Try a new station.