Adding a marker to a Labelled Graphic (no visible add button)

Writing a course and wanting to use a Labelled Graphic to explain a concept. To explain the concept, I need three (3) or more. 

When I add an image, I only get the option of two (2) Markers which can be edited. There is no option to add additional markers.

What can I do to add more and why is this not working today - in the past I have built courses with numerous Markers on a Labelled Graphic.