Double shadow from an object??

Question

C++ / C#

Hi comrades, maybe someone came across.
A very strange situation is when an object is on the ground, one shadow is visible from it, but when it stands on this slope, two identical shadows are drawn.
1. the mesh has nothing to do with it, I tried the sphere standard, etc.
2. rummaged through all the shadow settings in the quality settings, could not find a solution
3. there is only one light source, global
4. the shader does not matter, I tried with different and standard

Answer 1

The angle is not very clear. I will assume that the white path is a separate object, i.e. everything is like this:
In my screenshot, the shadow is duplicated because the middle cube has Cast Shadows turned off. In place of the second shadow from the sphere, there will be a shadow from the cube, if it is turned on.