RoboHelp Search removes drop-down header
On one page I have the following drop-down headers:

If I search "animation end", words from which are found in a few of the drop-down sections, the user sees this once they click on the search result:

This happens with the Responsive HTML5 output that is hosted on a server.
Without the server, it works properly, showing all the drop-down headers:

Why is this happening? How can this be investigated/fixed?
Thanks
