Linked PDF does not highlight search terms

[TechWriter57]

RoboHelp 2019

I brought a PDF in as a linked file and TOC'd it as a file.

In the ResponsiveHTML5 output, the PDF opens in a browser as expected and find the search term, but the term does not appear highlighted.  I have tried this is Chrome and IE.  

I have also checked that highlighting is selected as a property in the Word doc when saving as PDF.

How do I get the search terms to appear highlighted in the results when searched in RoboHelp?

[Peter Grainge]

I'm not sure it is meant to but to check I need to know more than 2019. Sorry but I can't remember which version everyone uses. Classic or New UI? Also which responsive layout?

[TechWriter57]

RoboHelp 2019 New UI

It turns out its OK for the user to be using the search functionality within the PDF itself, so its no longer an issue.  But, I would like to know why I'm not brought go to the location of the search term within the PDF itself when I click on a hit within RoboHelp.  Also, why the term isnt highlighted when I find it.

[Amebr]

I would say it's because the pdf is not HTML output, so the javascript that makes the text highlight and jumps to the location can't work in the pdf.