Reproduced on https://school.moodledemo.net/ with default theme

1. Access a mod's edit page
2. Scroll to Restrict Access section
3. Expand Restrict Access section, this should display the words "Access Restrictions" and the RA editor.
4. This should expand and collapse happily
5. Select Expand All
6. RA section should expand and collapse happily
7. Select Collapse All
8. RA section along with other sections should collapse
9. Expand RA section
10. Only the "Access Restrictions" words reappear, not the actual RA Control