Finally got my rig running again. I lost nearly 5 gallons of hydraulic fluid. Not fun and what a mess. Didn't get to perform your test, but I'll try tomorrow.
My L-39 easily picks the front end off the ground.
With the anbo grapple on, big stumps & rocks can pick the rear off the ground.
You appear to have a problem with your hydralics.
I have lifted 2000 lb + granite steps, and set them in place for a set of stairs.
I presently have an electrical problem @ 52 hrs.
I'll start another post seeking the groups input.