Indexing product_cat

I’ve been struggling to index the taxonomy type ‘product_cat’. I’ve selected it within the indexing settings, turned on indexing for taxonomy terms, rebuilt the index multiple times, increased the weight for ‘product_cat’, and tried several code snippets I found on the Relevanssi site included below.

add_filter( 'relevanssi_content_to_index', 'rlv_parent_categories', 10, 2 );
function rlv_parent_categories( $content, $post ) {
	$categories = get_the_terms( $post->ID, 'product_cat' );
	if ( is_array( $categories ) ) {
		foreach ( $categories as $category ) {
			if ( ! empty( $category->parent ) ) {
				$parent = get_term( $category->parent, 'product_cat' );
				$content .= $parent->name;
			}
		}
	}
	return $content;
}

add_filter( 'relevanssi_modify_wp_query', 'rlv_include_product_cat' );
function rlv_include_product_cat( $query ) {
	if ( isset( $query->query_vars['product_cat'] ) ) {
		$query->query_vars['tax_query'][] = array(
			'taxonomy' => 'product_cat',
			'field'    => 'slug',
			'terms'    => $query->query_vars['product_cat'],
			'include_children' => false,
		);
	}
	return $query;
}

I’m out of ideas at this point. Could someone give me some advice?

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