This is an expandable node, contained within every course, that doesn't get a unique id/key like the other expandable nodes do. Expanding the node for a course further down on the page impacts the first node with this id, meaning the user can't see the participants content for the node they actually clicked.
- Make a site with 2 or three courses
- Add the nav block to the dashboard
- Expand the course participants node for the first course
- Now, try expanding collapsing the same node for another course and notice it affects the first course's node.