Porsche 987.2 Boxster J.H - Problem fuel Smell inside the car specially full tank

Fuel vent solenoid - Checked already using drive links - clicking noise can be heard
Customer complain - Every time he fills up the tank to full - Strong fuel smell inside cabin
Note: The only mark on the fuel tank is on top of the fuel neck - leaking down to the bottom
Looks like small tiny crack on the plastic causing fuel smell only when 100% full.