I've been struggling with this issue for a few days. I have a content type with 3 required columns with a dotx template. When I user creates a new document using that content type the Document Information Panel displays the columns but the 3 required columns are not required. I'm not sure where's it's failing, perhaps it's referencing the wrong content type? I'm not clear how Word contacts SharePoint to get the columns and associated data.
Any help would be great. thanks.