I found a workaround, i added to functions.php the below code :
This code checks if current page is page or not. If it’s not page that means it is
mysite.com/watches/term/
otherwise if it is page
mysite.com/watches
So problem solved.
add_filter('template_include', 'template_include');
function template_include($template) {
$post_type = get_post_type();
if(!is_page() && $post_type == null && !is_archive())
return get_stylesheet_directory() . '/taxonomy.php';
return $template;
}