I have a 2016 1025r tlb with a 60 inch autoconnect deck. I’ve been doing some work with my 4ft box blade and the rockshaft lever got real easy to move and it won’t hold the box blade. I’ll pick the blade up and drive the tractor a little ways and all of a sudden the blade is dragging the ground. It will hold it if setting still. I checked the hydraulic fluid and it’s full. It never used to do this, does anyone have any idea what’s wrong?