Top Results is the one of the unwanted feature which outlook introduced and many users are not comfortable with it. I personally got affected with this feature when I was accessing my work mails.
This feature shows any random mail in Top Results which may not latest mail from your mailbox. Even after making change in settings as Newest on top with date wise outlook ignores that and it will pick one mail and it will show in Top Results. To get rid of Top Results search feature please follow below easy steps.
Go to Outlook File Menu and click on Options
Go to Search Tab and Un-check “ Show most relevant search results on top’
And save it.