Array in ScriptableObject made with a SO Creator script

Hello,

I created a simple project where a "GridCreator" script create ScriptableObject in assets folder "Grids" with an ElementData[ , ] attribute. The row and column Lenght of ElementData[ , ] are initialized and then the content is assigned, all in that GridCreator script. However, when I try to read the data inside the attribute, it return empty.

I understand that the problem is about Serialization. But I can't figure out a way to make it work.

I was using multidimensional array before but learned that Unity did not support serialization of such things. That is why I went for an array of a class which have an array as attribute.

Here is the entire project on a Bitbucket repository