Having had the tank in my hands this doesn't make sense. The JFC only moves the inner chimney, shouldn't have any effect on the volume of the tank.So, some issues are emerging: In some cases I experienced flooding after filling it. After a bit of research I suspected that the JFC actually pushes juice into the chamber when closing it. Think about it, it makes sense: It makes the tank volume a bit smaller, so the juice has to go somewhere, which is a) into the tank or b) into the chamber.
Today I tried to:
1) Close the JFC.
2) Vape it dry.
3) Opening/closing the jfc repeatedly about 5-6 times (with the top cap closed).
After that I had juice pouring out the airflow holes.
Do you still have the o-ring at the base of the deck?