I'm only on my second tank of fuel, but I've not experienced this.
When I refilled the first time, I wondered about expansion because it was a very hot day, so I was a little concerned about filling it so high that it would vent gas.
In the end, I only squeezed in 2.4 gallons (but that took the gas to the point where it was just beginning to come over the top of the round plate in the filler. When I started the bike, the top segment of the "gauge" wasn't lit, so I apparently had room to go.
Anybody have any advice as to where to safely consider the tank "full" while filling up?