I bought the stainless steel MES 30" from QVC about 2 years ago and can't figure out a unique problem I'm having. I've looked up the other models of the 30" MES and they all seem to have a clip that locks the door when closing the smoker. Mine has a handle on the front that acts like a deadbolt on a doorknob where i have to spin it one way or the other to get it to lock on the inside of the smoker. The problem is that it's become very loose from many uses and even after tightening the nut down on the inside, the knob is still loose and difficult to lock in. Does anyone have any advice on a fix for this or a way to get that part? i've tried masterbuilt's website and can't find that specific part as if its some kind of special model that they no longer support.