I am not that familiar with the 2605H. However I believe that all came with draft control. It would be the taller of the two outside levers next to the 3point hitch controls. The plastic handled unit is the position control, the taller of the outer levers is draft control, and the smaller of the levers is reaction control. Draft control is used with ground engaging implements such as plowing. Most folks don't use it. I believe it should be as far forward as you can make it. The short lever is response control it determines how fast your 3pt responds. Move it one way and the 3pt will gently move, move it opposite direction and it will move rapidly.
I believe that your draft control (middle) lever is in the wrong position. Move it to the opposite end of its movement and see if that helps, if not them move it to the opposite end of its travel and try again.
Also please post back with your findings. If your having this problems, most likely others will have the same issue. It is helpful for others to see how you solved this.