I'm getting similar issues with the autoleveling. Out of the box my machine went through the auto level process without a hitch, blue light and all. But with a print that covered much of the sheet my first layer was noticably thin towards the front left corner and it appeared to continue dragging exccess material towards the back right fdor the next few layers. In the end it gave me a passable print of a pretty simple object but it was less than ideal.
After a quick check I was concerned there maybe some inconsistancy in the tension of the rollers underneath. I subsequently disassembled the y axis to the point where I could access all 4 rollers, set the adjusting nuts to the midway point and undid checked the static rollers to the same tension.
Though the issue is somewhat improved it persits and I take issue with the fact that a mechanical solution has done what the auto leveling should do. I've seen no proof the auto leveling does anything but turn on a blue LEd and go through the motions.