Article ID: 2304855 - View products that this article applies to.
Microsoft SharePoint is not crawling the draft items to return in search results.
By default SharePoint only crawls major versions of files and draft items are only viewable by their creators. SharePoint is behaving as expected out of box.
This behavior can be altered in Document Library Settings -> Versioning Settings -> Draft Item Security
Select the option Any user who can read items.
This will allow all users to see draft items including the crawling account.