How is an attribute value SLUG created?

Yes, I am assigning global attributes to the product, here is my code.

$attributes = wc_get_attribute_taxonomies();
	foreach($product_data['atrebuts'] as $key=>$val){
		foreach($attributes as $value){
			if($value->attribute_label == $key){
				if($val[0]){				wp_set_object_terms( $post_id, $val[0], 'pa_'.$value->attribute_name);
	             $slug = $value->attribute_name;  
$terms = get_terms( array('taxonomy' => 'pa_' . $slug,'hide_empty' => false,));	
				foreach($terms as $term_id){
					if ($term_id->slug==sanitize_title($val[0])){$term_id_id=$term_id->term_id;$term_tax_id=$term_id->term_id;}
		}	
               	$new_attr = new WC_Product_Attribute();
                $new_attr->set_id( $term_id_id ); 
                $new_attr->set_name('pa_'.$slug);
                $new_attr->set_options([$term_tax_id]);
                $new_attr->set_visible( true );
                $parent_attributes['pa_' . $slug] = $new_attr;
                $product->set_attributes( array_values($parent_attributes) );
		$arts['pa_'.$slug] = array(
			'name' => 'pa_'.$slug,
			'value' =>[$term_tax_id],
			'postion' => '0',
			'is_visible' => '1',
			'is_variation' => '0',
			'is_taxonomy' => '1'
			);
								}
				}
			}
		}		
                $product->save();
               update_post_meta( $post_id, '_product_attributes', $arts);

But there is a nuance here, when determining the term_id, I cannot correctly determine this ID for all parameters.

If you check by name, then there is a problem with a dot and a comma, you get a different name for the same values. You can try to bring it to one type, but the slug has exactly a unique meaning and you don’t need to connect various functions, and here I can’t understand why the slug began to turn out as an ID, and not sanitize_title($name)