This is because you are using construction geometry instead of real geometry. An easy way to tell what you are working with, is the line color. By default construction geometry is Magenta, and real geometry is White. There is a switch at the top of the "Create 2D" and the "Contour" dialog box that allows you to switch between Geometry and Construction. You can also modify the geometry on your existing Workplane. Open the Modify 2D dialog box. At the bottom, there is a Convert Geo function. This will change Geometry to Construction Geometry, and Construction Geometry to Geometry. Note that you cannot change infinite Construction Geometry to Geometry.
