Generally fill my 2009 F250 gasser at home from my barrel. Tried to fill the other day in town and could not get the nozzle to stay on even on the slowest setting. Finally gave up after $5 bucks worth enough to get home. Have had this happen before with my 2011 Chevy but hasn't happened in a long time. Is my vent system plugged up? If so I am not getting any warning lights in the dash.