I found something strange in my installation of DNN 5.6.

I have two custom roles set up. 

First is Publisher, this is a Global Role. A person assigned to this role is supposed to be able to Add pages, Edit pages, Add modules and edit modules. I went to all pages and assigned this role to Edit and propagated to all children

By itself, this role does work as intended, the users can create and edit pages, add and edit modules, with a full list of modules to add in the drop down of the control panel. (user is also member of standard roles, subscriber and registered user)

I also have another Role, Stofl. This role is only set up to allow access to a particular area of the forums module. This role is obviously custom and is in a custom role group (not global). Members of this role, do not have permission to edit or add anything. 

If a user is a member of both roles. Stofl and Publisher, they are able to add new pages, edit pages, edit existing modules on that page, but are not able to add new modules to any pages. The drop down is disabled and appears to be empty.

What is happening here? Why would the assignment to a custom role, exclude them from a privilege given to them by another role? Is it because the offending role is in a custom role group because the global role, Register User does not prohibit them from adding new modules.