I've been banging my head against the wall for last couple of days trying to exclude a category from an archive of easy digital downloads, which i am displaying in a custom widget, however i cannot hide a category called 'custom-project' no matter what i try.

This is the code i am trying to use, based on instructions from https://codex.wordpress.org/Class_Reference/WP_Query

    $argsQuery = array(
    	'posts_per_page' => 3,
    	'post_type' => 'download',
    	'tax_query' => array(
    		array(
    			'taxonomy' => 'download_category',
    			'field' => 'slug',
    			'terms' => 'custom-project',
    			'include_children' => true,
    			'operator' => 'NOT_IN'
    		)
    	),
    );
    $get_latest_downloads = new WP_Query( $argsQuery );							
    $i=1;
    while ( $get_latest_downloads->have_posts() ) : $get_latest_downloads->the_post();
    
    //WIDGET BODY CODE
    
    $i++;
    endwhile;


I also tried using 'cat' instead of 'tax_query', but with no success as the category 'custom-project' is still displaying inside the loop of posts.

    $argsQuery = array(
    	'posts_per_page' => 3,
    	'post_type' => 'download',
    	'cat' => '-5',
    );
    $get_latest_downloads = new WP_Query( $argsQuery );							
    $i=1;
    while ( $get_latest_downloads->have_posts() ) : $get_latest_downloads->the_post();
    
    //WIDGET BODY CODE
    
    $i++;
    endwhile;

					


I am certain that slug name and category ID are correct. Any kind of help is greatly appreciated.