2002 Hyundai Sonata Gas Tank Issues

Engine Performance problem
2002 Hyundai Sonata

I bought a 2002 Hyundai Sonata. Gasoline has flowed flawlessly into the gas tank for years. About two months ago, something changed. Now it is impossible to fill thirty cents worth of gas without the nozzle kicking off due to some kind of flow restriction. I have looked down the tank neck and see nothing in the way. There has been no damage to the outside of the tank. I don't know if there is some sort of vent on the tank that might be causing this, or if I'm just going crazy. When it takes 25 minutes to fill your tank, something is wrong. Any ideas?