Sounds like the ends of the ramps are squared off and ride high enough above grade that they cause the ramp to tilt back and the other end raise up. The end could be tapered by welding a piece of angle iron across the end in a Vee configuration with the point of the Vee becoming the very end of the ramp to create a tapered end. OR you may need to put blocks under the end of the trailer so it don't squat when you get the bulk of the weight on the very end of the dovetail. The blocking also helps avoid broken springs.
Blocking it or having drop down stands welded to the back of the trial.
