Dealer is wrong. The fronts can work independently, but when auto-leveling the centers and rears lower to ground, then all six adjust accordingly. Give Lippert a call and they will walk you through trouble-shooting.
--2005 Ford F350 Lariat Crewcab 6.0, 4x4, 3.73 rear
--2016 Montana 3711FL, 40'
--2014 Wildcat 327CK, 38' SOLD