make sure you are not popping the joystick into float when you push it forward. It is very easy to do and then the bucket will just bounce along the ground. There is a fint line between no pressure and dropping into float you have to hold to and then it will work. too much and you will pick it up off the ground. too little and you won't grade anything. it takes some practice to figure it out. I had the same problem until I figured out how to work it. I have had 5 john deere tractors over the last 15 years and I am pretty sure this is your problem. Play around with it a little. You will eventually figure it out and once you can feel where you need to stay with the joystick, it will be easy. hope this helps.
too much stuff