Problems with the pump shutting off all the time can be caused by evaporative emissions control problems, but I don’t know that can cause the opposite case too. The absolute worse car I’ve ever had for this was an old Chevy truck with the (notorious) saddle-tanks-- the filler hose was damn near horizontal and no EVAP controls to speak of. Half the gas pumps in town wouldn’t put gas in at all (or I’d have to hold the pump at half flow or hold the nozzle upside down so the shutoff hole was on top) and the other half would surge over like crazy and spill gas everywhere if you didn’t listen and shut it off as it was nearing full.