2006 Kia Sedona Fuel Tank

This is perfectly normal. It happens because as the fuel goes into the tank it splashes and bubbles. As the tank gets closer to being full, the displacement caused by the bubbles forces the gas to go up the pipe that feeds the tank and triggers the "full" switch on the pump nozzle. Of course it backsplashing is NOT normal .. Perhaps you should try a different pump station. also try holding the nozzle at a different angle , some vehicles' tank inlet is just set at a funny angle and "confuses" the gas station's pumps in wether your tank is actually full or just bubbles making it think its full.