I have a few issues with my kayfun leaking a lot after filling up. I do fill from the top since I do not have a needle bottle to use the hole for. I've made sure the rubber grommet is in place and everything, I even flip the tank and screw the top to make sure it creates a vacuum but it still leaks. If I flip over the kayfun it leaks drop after drop from the drip tip after I try to suck the juice out of the tank that is creating the gurgling when I'm vaping. I've also made sure to cover the airhole when top filling and flipping over the tank to create the vacuum but it still leaks a good amount. What am I doing wrong?