A single action airbrush like the 200NH can do this with really thin paint because the needle doesn't move and the nozzle stays open between strokes. Paint leaks onto the needle tip and blows off when you press for air. It's worse when the needle is set way back. And, a very low viscosity thinner like lacquer thinner makes it more likely to occur.
Try thinning a little less and setting the needle a little farther forward.
Don