I assume the Elastic Modulus in the isotropic material properties is Young's Modulus (G) so it should have a relation with Shear Modulus and Poisson's ratio as in the equation below:

E=2G(1+v)

I tried calculating several materials and none of them meets the above equation. I am wondering what Elastic Modulus stands for here? If it is not Young's Modulus, what is it?

Elastic modulus is the Young's modulus.

I know it was there when you found it. I'm just arguing that there is no way for the software to use all three of these numbers. In fact, I'm pretty sure shear modulus does not enter into the FEA calculations. It's just there like a reference dimension. Consider the shear modulus to be in parenthesis.