Just something else to ponder, how much current is your jack drawing?
I recently installed a BMV-712 and it gives you actual AMP draw. I tested various circuits for grins including raising my 30' up via the Husky tongue jack. Just trailer only not connected to TV and setting the bars it only pulled 6.4A.
Maybe your jack is adding extra mechanical friction load that the fuse says nope that's too much current. I just checked I installed my Husky 9 yrs ago. Goes up, goes down.
2005 Dodge Ram 2500 5.9L 6 Speed
16" Michelins, Hi Spec Wheels, Max Brake, Dexter 4 Piston Disc Brakes, Carslile Actuator, Equal-I-Zer, Dill TPMS. Campfire cook. BMV-712