I’m using 2.3D9, but this has been happening with all of the 2.3Dx releases, I believe. Outlining and contouring have a fundamental disagreement on the limits of my part.
In addition, it seems tabs might be ignored by the contouring pass. That doesn’t show in the above image, because the contours aren’t going to the edges of the part for some reason. (I think they did, in a previous Dx release, and it was clear that the contour cuts were going to cut away the tabs left by the outline pass.)