Consider a screnario where people search result for last name ‘Sam-Savola’ (with a hyphen). A SharePoint people search does not list out any result, whereas if search is made for “Sam Antoly”, you get the desired results. The same issue happens if you're searching for “Cohen, Antony” (name with a comma). The difference in search results can even vary from machine to machine. For troubleshooting, one should start by checking the crawl logs to ensure that user profile was successfully crawled and indexed. This issue was found to be a localized issue. On further digging around, it was found that, it is due to customization of SharePoint Search Core Results webpart which considers user’s browser language setting while displaying search results. To fix the issue, try to add "en-us" language as your default language on your browser.
Craig Lussier edited Revision 2. Comment: added en-US to tags and title
Ed Price - MSFT edited Revision 1. Comment: Font and title guidelines. Added a tag.