So, a "shadow object" blocks the sun's rays that would have shone on the moon...
Why, then, can you not see the shadow object when the sun is shining on it?
Also, if the sun's rays are vertical, how is the moon illuminated at all? If the moon is the same altitude as the sun, there would be no illumination if there are no horizontal sun rays. If the moon is below the sun, the surface facing earth would always be in shadow. The second seems more likely since your explanation for solar eclipses is that the moon passes between the earth and the sun.
Your explanation is flawed, and the notion of an invisible shadow object is absurd.