On the first image:
That looks correct to me. The shadow from the rightmost cube is projected onto the side of the center cube.
And the shadow of that center cube is projected onto the side of the leftmost cube.
On the second image:
That also looks correct to me. If it was "cutting" the cube like butter
you wouldn't see that the shadow is "lifted up"/"folded up" a bit.
Maybe just play a bit with the light height/position. Make it a function of time to also vary the light's position.