Hi Debbie and welcome to the forum! I moved your question to its own thread in this section because I think you will get better responses here.
If the hydraulic system is full of fluid and there is no binding along the tracks, I wonder if possibly the manual lowering valve is slightly open? You can find this thing attached to the pump near the hydraulic reservoir. Some of them look like a "rod" and others, I think are sort of like a rotary knob. If it's the knob type, you turn it to open or close it. If it's the rod, I think it is moved side to side or up and down (I don't have that kind so I don't really know how it works).
If this is not your problem, you MIGHT have a leaking seal in the system that would require a rebuild.
Hang in there. Someone will be along with batter thoughts, I'm sure.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew