It's the interaction between the dispenser and the car. I've driven a few vehicles that would have trouble at some dispensers. With my vehicles, I was able to make it usually work by holding the handle up a little and avoiding stations with dispensers that didn't get along with my vehicle.

It seemed to me that sometimes the angles would mean the gas splashed off the filler tube in the wrong way and confused the dispenser. There's a bunch of different ways to run a filler tube, and different dispenser handles, so I adapt.

In my case, my first vehicle was older than me, so you don't exactly complain to the manufacturer that it has trouble filling at some stations. When newer vehicles acted the same way, I already knew how to jiggle the handle to fill up, so I just wouldn't get to wash my windows at the same time as I filled up, if I went to the wrong station. I wasn't ever one to buy stuff inside while the vehicle was filling, so not a big loss of functionality.