Evap test question…

Could anyone offer me some advice on this… when I put smoke at the front evap hose going to the back and use a scan took to close the vent valve I still get smoke basically on the side on the fuel fill spout behind the left rear tire. It’s an opening maybe 6” from the top. Is that normal? Also when I command the valve open and closed I don’t hear it at all like I have with other cars in the past but you can feel it doing something. Any thoughts.