fx:Array doesn't works with Object or ADGColumns

There's a problem that we are creating AdvancedDataGrid in Base Class and ADGColumns are created In child class which is starting with tag . AdvancedDataGridColumns are created within tag that is not working in SDK.
Here's the example please check the issue if you have time, In debug mode, there's no exception and In Elements tag ADG is not added there
Zip File: https://drive.google.com/file/d/141cTBvSKM67ZM3klbQCGLb-rPqj63pNE/view?usp=sharing

Even a simple example using fx:Object within the tag of fx:Array is not working,I have also tried making [Bindable] var in script block with the same name but it doesn't work.
Simple Example File : https://paste.apache.org/fdr2y
Please help