The title attributes for your menu links can disrupt any jQuery that you’re using for a dropdown. Use this to remove it.

 function my_menu_notitle( $menu ){ 
 
return $menu = preg_replace('/ title=\"(.*?)\"/', '', $menu ); 
} 
add_filter( 'wp_nav_menu', 'my_menu_notitle' ); 
add_filter( 'wp_page_menu', 'my_menu_notitle' ); 
add_filter( 'wp_list_categories', 'my_menu_notitle' );