Resource being assigned to projects with no project role

Why does a resource not have a role when being assigned to a project?

This is due to the enterprise role of the user being assigned not having a default role set for the project type(s).

The default project role specifies what role to give a new team member who is added to a project as a result of an approved resource request in Team Manager.

You can edit the enterprise role and assign defaults for each project type.