Hi,
Can you please be more specific about the issue:
– Have you excluded or included a post category?
– What type of results do you have selected? (posts, pages, custom post types, categories, tags etc..?)
– Does the search display posts (or cusotm post types) from the excluded categories?
– Does the search display posts beside from the included category?
Sorry about the questsions, but since I can’t see the issue, I can only guess.
If you want to search posts from a specific category only, I suggest checking this knowledge-base article: Searching within given categories only