Don’t know jack

What is up with the jacks on these semi-hollowbody Epiphone guitars.  When I was shopping for guitars in the stores, I often saw Epiphone Dots and Sheratons with the jack missing inside the guitar.   How can that be good for sales?!  And when reading in the Epi forums, I saw folks complaining of this happening to them.  Does this happen on the more expensive Elite Epi’s, or other semi-hollow body guitars?

Update: I added a 1/4″ inner-tooth lock washer between the nut and round washer, and it has stayed tight ever since.

I never thought it would happen to me.  I made a point of periodically hand-tightening the jack when plugging in a cable, just to be sure.

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