Unhiding a section which contains hidden resources/activities makes all of the content appear unhidden.
This is due to the fact that the AJAX code uses CSS styles to determine what was previously shown/hidden.
- Hide some resources
- Hide the section
- Refresh the page (or do something which causes the page to be refreshed)
- Unhide the topic -> all resources appear unhidden
- Refresh the page -> all hidden resources appear hidden again