So I made a new custom post type X.
I also made a new post template for this new post type (a PHP file).
When I go to my normal posts, this template is available under "Post Attributes".
I enabled Supports > Page Attributes in the post type settings.
But when I go to custom post type X, I can't select any template under "X Attributes". All I see is an 'order' field, where I can insert a number.
I want to be able to select my custom post template for my custom post type created with MetaBox.