I am assuming your front jacks are electric so I am sending this drawing.
based on what you telling me I am assuming it is the Jack nut that has let go to the top of the adjustable leg.
Rethinking this. The drive pin on the top of the jack screw 920-00 may have sheared and allowed the jack screw to drop down. I would check that first. You can access it by prying the top flat cover off the top of the leg and look at the 910-00 16T gear.
Venture or Lipper may be able to send you a replacement leg.
Good luck and safe travels.