I recently ran into the issue of a document appearing in search results that didn’t use the name field OR the title field. I was perplexed by this until checking the search schema for the “Title” field. In an attempt to be helpful, there’s a property called MetadataExtractorTitle that was given higher preference than the actual title field. To fix this, I simply had to bump it down the list a bit.
Scenario
The document in question is a SharePoint Governance meeting agenda named SP Governance – 2017-11-17.
It appeared correctly in its library, which is to be expected:

And a look at its properties revealed there was no Title value, meaning it would default to the document name.

However, when searching for “SP” I found the document listed as “Agenda.” This was used because the MetadataExtractorProperty found “Agenda” within the document as a potential title (as the first line of the document).

Solution
Note: You must be at least a site collection administrator.
Go to Site Settings at the top level of the site collection for the document library.

Choose “Search Schema” under Site Collection Administration (not just “Schema” under search – that’s only site level)

Search for title and edit the property

Move “MetadataExtractorTitle” down until it’s beneath ows_Title. Click OK when finished.

Checking your work
After fixing the schema, go back to the document library and re-index it to check. (Library Settings –> Advanced Settings –> Reindex Document Library)

This will have the library re-crawled during the next incremental crawl (interval depends on administrator settings). Alternatively, you could trigger it immediately or run a full crawl.
Once the crawl has run, try your search again. Your items should now have a correct title when appearing in search results.
