Object not falling
because you are setting it to be a static body with BodyType.STATIC. You need BodyType.DYNAMIC to make things move by themselves....
Haxeflixel. Nape. DistanceJoint debugging. Drag sprite to area
debugging,haxe,haxeflixel,nape
Give Drag a function like "destroyConstraints()" and set mouseJoint.space = null inside that function. In collideLightBox, call drag.destroyConstraints().