I have a question regarding where you said that you cranked up your Scamp
5" to clear the hitch and then did not have enough down left. Did you not have enough down left to level your Scamp
or not enough down left to attach to the hitch?
If not enough down left to level the Scamp maybe you should not pin the feet all the way to the ground before cranking up.
If not enough down left to attach to your hitch maybe this could happen, if you used the same truck that you set up your Scamp with, is that you have done something to lower the height of your truck while unhitched. Or, something is wrong with your landing gear jack. The 400+ revolutions and not topping out sounds suspect. Good luck.