On my older jack, the ground was thru the bolts to the frame.. That was the jack that didn't work that one time for me.
I've since replaced that jack with a new one (the old one finally just broke in the gear box) and the new one has it's own ground wire directly to the battery.
Dunno what else to suggest since you seem to have a different issue than I did with my old jack.
Again, good luck!
Mitch
2013 F150 XLT 4x4 SuperCab Max Tow Egoboost 3.73 gears #7700 GVWR #1920 payload. 2019 Rockwood Mini Lite 2511S.