Extra translations in Storefront child theme not loading/working

I’m using WC with the Storefront theme and have created and activated a child theme. As per the instructions in wp-content/themes/storefront/languages/README.md I created de_DE.po and de_DE.mo in the languages subdirectory inside my child theme’s folder. The de_DE.po contains a single translation:

#: woocommerce/myaccount/dashboard.php:59
msgid "Your purchased content"
msgstr "Deine gekauften Inhalte"

I’ve duplicated the file wp-content/plugins/woocommerce/templates/myaccount/dashboard.php as per the instructions in that file in the subfolder woocommerce/myaccount inside my child theme. In that file I’ve added the following code to display the translated text:

<h3><?php printf(__('Your purchased content', 'storefront')); ?></h2>

However, the translation isn’t showing, instead it’s just showing the original string. All other strings are showing up in German, the locale is set to de_DE.

As I understand it, the code in wp-content/themes/storefront/inc/class-storefront.php already loads any child theme translations/textdomains with this code:

load_theme_textdomain( 'storefront', get_stylesheet_directory() . '/languages' );

So I assumed I don’t have to manually add anything to my child theme’s functions.php. Nevertheless, I also tried loading the textdomain manually using load_child_theme_textdomain( 'storefront', get_stylesheet_directory() . '/languages' );, but that didn’t change anything.

I’ve also tried out different textdomains, e. g. the name of my child theme and “woocommerce”, which also did not work.

I’m at a loss what I’m doing wrong here. Any ideas?