Custom Type Selection based on Category

Hi all,

We have Windchill PDMLink 10.1 M020 installed and added one custom class below CAD Document.

When we try to create New CAD Document from Workgroup Manager, it asks for "Category" and "Type" selection.

For "CAD Part" category, we are able to see custom type in the "Type" list of values.

But, for "Assembly" category, the custom type doesnt show up in the list of values.

Does anyone know why? How to get it visible there?

Thanks!