I use all Kangers, including the T3S and have not had this issue. But I also don't screw anything together tightly because the guy who sold me my first outfit said air flow is important. Someone at work (who is a vaper) looked at my PV and they took off the kanger then put it back on. When I went to take it off to re-fill I had to really twist it, so my "tight"is probably a lot less than other people's "tight" lol.
P.S. - I also clean out the air tube with a Q-tip every time I re-fill and also clean the battery
threads and connections every time I charge. No particular reason other than the stuff isn't cheap and me mum always said if you take care of something, it will take care of you.