Remove taxonomies using register_post_type_args

Question

The theme I'm using is adding taxonomies to CPT using register_post_type and 'taxonomies' => array('portfolio-cat') as one of the arguments.

I need to remove that particular taxonomy using register_post_type_args.

I have tried with:

add_filter( 'register_post_type_args', 'change_portfolio_post_type_args', 10, 2 );
function change_portfolio_post_type_args( $args, $post_type ) {
    if ( 'portfolio' === $post_type ) {
        unset($args['taxonomies']); // Not working
        unset($args['taxonomies'][0]); // Not working
        $args['taxonomies'] = array(); // Not working
        $args['taxonomies'] = array('category'); // It justs add another taxonomy
    }
    return $args;
}

How can I remove it, without touching theme core files?

Answer 1

Did you try this? Here: unregister_taxonomy_for_object_type()

Read more: https://developer.wordpress.org/reference/functions/unregister_taxonomy_for_object_type/

function unregister_portfolio_cat_for_portfolio() {
    unregister_taxonomy_for_object_type( 'portfolio-cat', 'portfolio' );
}
add_action( 'init', 'unregister_portfolio_cat_for_portfolio' );