Category post count is not correct

When I go to Posts Categories, some categories show that they have a post. See screenshot. But there are no posts linked to that category. When you click on that 1-number, no posts are shown.

This is an issue because my blog page shows the category title and description even if there are no actual posts linked to that category (Wedge-system - see screenshot).

This is how I loop over all the categories and show the posts from that category:

?php
$loop = new WP_Query( array(
                            'post_type' = 'Post',
                            'posts_per_page' = $post_per_page,
                            'tax_query' = array(
                                array(
                                    'taxonomy' = 'category',
                                    'field'    = 'id',
                                    'terms'    = array( $category-term_id ),
                                    'operator' = 'IN'
                                ),
                            ),
                        )
                        );
?

?php while ( $loop-have_posts() ) : $loop-the_post(); ?
    /* post template here */
?php endwhile; wp_reset_query(); ?