Are all your hydraulic levers in the center detent position? Make sure one is not in the down or "float" position.
This may not be your cause but I will mention it just to cover all bases - When you changed fluid, did you also change the filter? Is it the Deere filter recommended for your 322?
This may not be your cause but I will mention it just to cover all bases - When you changed fluid, did you also change the filter? Is it the Deere filter recommended for your 322?