Custom Font deleted after every update

Hi!

Please add following code to Functions.php file of your child theme

function theme_name_scripts() {
	wp_enqueue_style( 'style-name', '//cloud.typography.com/1234/5678/css/fonts.css' );
}
add_action( 'wp_enqueue_scripts', 'theme_name_scripts' );

You should replace the 1234/5678/css/font.css link with your CSS key. I am sure they can help you with how to find it as well :)
Please also see – http://kriesi.at/documentation/enfold/using-a-child-theme/

Regards,
Yigit