We can only get about 1.5 gallons of fuel in tank before nozzle clicking off and overflowing. Today I found that immediately after clicking off I hear gurgling and then can put another gallon or so in. This is with really feathering a slow fill rate and at 2 different gas docks. Dock attendant thought it sounded like a vent line problem. Any others experience this and what the solution? Thx.