is it u do multiple draws in quick succession on your atty ? For me when I want a fast hit I will quickly draw until the tank is hot - there is a lot of vapor that will condense back onto the mouthpiece and will backflow into the air hole - this will cause leak. If i slow vape (draw every few seconds, like when i makan with friends) then wont have leak.

damn bloody lot of issues with these older devices. Mine conk out after 1.5 years, had to buy an Eleaf with in built battery. So small and cute.