There are indeed a few issues here.

• Firstly, you've got a gap between your filled shadow and the form casting it. I'm pretty sure your intention here is not to have the upper sausage floating above the lower sausage, but rather to have it resting upon it. Thus there should be no gap between the upper sausage and the shadow it casts, because there's no physical space between it and that surface.

• Similarly to the first point, where the cast shadow transitions from the lower sausage to the ground plane, you have that shadow get disjointed, effectively shunting it over a measure. But there's no such break in the upper sausage, nor is there any such break in the surfaces the shadow is being cast upon (the lower sausage is touching the ground plane, so the shadow doesn't have to jump any sort of a gap). So there should be no such break in the shadow being cast either.

Here I've marked out what the cast shadow would look like. It runs along the surface of the lower sausage (even hooking back a bit along the bottom edge) before transferring to the ground plane. I'd also advise you to pay closer attention to your contour lines, as their alignment tends to be quite skewed.