I fought with this for some time as well. Read the threads, removed the roll-over ball , which helped, but didn't fully correct. While under there I saw the fundamental issue on mine. The fill line does not go into the top of the tank, but into the side, hence when you start to get 1/2 to 3/4 quarters full (depending on angle of the tank when filling), the fuel in the tank starts to cover the hose inlet to the tank.
Only way around that I found was: 1st) do my best to have the fueling side of the camper on the high side if possible. 2nd) once you get 1/2 or above you will have to "baby" the fuel into the tank. Note, I have not tried flipping the fuel hose nozzle as suggesting in previous post. I will try that next time out as well. But from what I saw underneath (fuel hose going into side of tank vice top, I still think when the fuel level in the tank starts to cover that inlet hole you will have to slow down and let gravity push the fuel out of the infeed hose & into the tank until it levels out again.