I bought my KFL+ early Feb
Never had an issue with it leaking though, i love mine.
Ditto had mine 2 weeks nearly now using in ''Nano'' mode so filling daily no issues what so ever.
Either the clones really are crap or lots of people can't build them right/well.
Zero leakage at all from mine. Unless you force it by flooding the chamber on purpose the blowing it out the airhole.
As long as the chimney o ring is seated correctly it shouldn't leak at all from either end. In fact my russian 91 sits in my laptop bag on a paps as a backup/ ever reliable device. I've never lost a drop of liquid.
Mason.