just encountered same problem in one of my projects, Even with FM2015. Perhaps this could help you, finding a solution for your problem:
This problem in our situation occurs, when the first paragraph in a document is filtered in HTML5 output. In our case first paragraph is a headline which should only appear in print output but not in webhelp. So we ignore this paragraph with the STS settings, and it doesn't appear in HTML5 Output.
This works well in normal HTML-Output, but in Fulltext Search data (and some others like Index-Files) the filename and not the first heading for HTML5 appears.
There are two ways to solve this Problem:
1. Use conditional text in FrameMaker an let FrameMaker not HTML5 Publishing process filter this content
2. Add die titel of the document to document metadata "File > File Info > Title"
(not sure if second solution is practicable as this is hard in translation processes)
Hope this helps
I believe this is fixed in either a patch or in Fm 2017. Ensure you have the latest Fm 2015 release, and if so, download a 2017 trial to test.
But make sure you do it on a non-production machine - you don't want to bork your existing install...
It's the latest patch of FM2015, and problem is still there in 2017 (for unstructured docs).
Re: FM2017 - did you apply the patches to the version you installed? Fresh downloads don't have the latest patches baked in.
of course, no complains without using latest patches :-)
and it's also comfirmed by Adobe at least for FM2015, but I also can reproduce this in FM2017. (not DITA, in FM2017 DITA is published another way).
So you have to work as described to solve this problem. FM struggles in HTML5-publication if first headline is filtered by STS-Settings. Then it doesn't know what to do, and takes filename instead for displaying title in fulltext search.
And even in index files and others (but the last ones don't come to UI, one encounter this when one wants to more than stanard-output.
You have to apply conditions in FM first or you have to put the title to file metadata.