Go to LW's menu bar, Tools -> Options -> Filters -> Junk, & choose to show junk at bottom of search results. That might be the reason. The junk results are being counted but not showing. Also, the junk filter does get it wrong so checking to make sure those files shown as junk are really junk & not good files.

Alternatively, you are filtering results to the side. Click on the (All) near the search filters to the left.

Attached Thumbnails