Woo doesn’t filter out products with hidden catalog visibility outside of main shop loop. This is important to remember when using the REST API for front end display or general search results. This code snippet will keep them from showing outside of the admin. Source: whoischris.com

remove-hidden-products-query.php

<?php
/**
 * https://whoischris.com/remove-catalog-visibility-hidden-products-in-woocommerce-from-search-wp-rest-api-results/
 */

add_action( 'pre_get_posts', 'hidden_search_query_fix' );
public function hidden_search_query_fix( $query = false ) {
	if ( ! is_admin() && isset( $query->query['post_type'] ) && $query->query['post_type'] === 'product' ) {
		$tax_query = $query->get( 'tax_query' );
		$tax_query[] = [
			'relation' => 'OR',
			[
				'taxonomy' => 'product_visibility',
				'field'    => 'name',
				'terms'    => 'exclude-from-catalog',
				'operator' => 'NOT IN',
			],
			[
				'taxonomy' => 'product_visibility',
				'field'    => 'name',
				'terms'    => 'exclude-from-catalog',
				'operator' => '!=',
			],
		];

		$query->set( 'tax_query', $tax_query );
	}
}