I have a Cobra, my son has a Cobra, both identical in every way. Mine works absolutely wonderfully. His he can't get to wick properly, dry burns, face turning inside out, the works.
The difference is, I wind my coil to around 1.8 to 2.0Ω. He winds his to 1.3Ω. The size of the wick in a Cobra just can't keep up with that much heat. You need a larger mesh, thinner liquid or more resistance. Will he listen? Of course not. Surprised no one has mentioned it already.