I will try to get a pic later. I have tried several speeds, all with the same result. When I lower the tip it will cut deeper but the bottom never levels out the rear is always higher then the front, consequently I never get a nice flat furrow bottom. this video show a very similar situation, notice on the second pass how the back end is way to high. the second half of the video it seems to be corrected but I have no idea what changed
https://www.youtube.com/watch?v=x5qzJAeoqDo