Edition: Professional, Business, Enterprise
User-level: Assistant Administrator, System Administrator
If you are adding a staff or contact to the project contacts list, and you are unable to select a specific role for them, it will be because the role is not available for that contact type.
To change this
Settings > Contact List > Roles.
Select the edit pencil to the right of the role you want to apply to a contact
Ensure the contact role or staff role checkbox is selected
Select the check button to the right