Expanding Assignment Feedback Comments broken on Complete Report

The plus icon to expand feedback comments for an Assignment on a user's complete report is not working.

To re-create:

1. Go to a course that has an assignment activity with user submissions and teacher feedback comments (long enough so they will need expanding)
2. Go to Participants
3. Click a user
4. Click "Complete report"
5. Locate the Assignment and Feedback Comments
6. Click the Expand/Plus icon

The Teacher would normally run this report, expand all the feedback and print that page to PDF to give to the student.