Thank you for contacting WPML Support. To take a closer look at link translation issue, please provide temporary access (WP-Admin and FTP Login info) to your site (preferably staging site), so that I can look into your setup and debug the issue.
Your next answer will be private which means only you and I have access to it.
=== Please backup your database and website ===
✙ I would additionally need your permission to deactivate and reactivate Plugins and the Theme and to change configurations on the site. This is also a reason the backup is really important.
Thanks for providing the login details. I have followed the below steps:
1. Went to the WPML >> String Translation page and searched for checkout page text “Wir verwenden deine personenbezogenen Daten” and assigned the correct German language.
2. Used the same [privacy_policy] shortcode in a translated string.
3. Searched for wp_page_for_privacy_policy domain and added the translated privacy policy page ID as trasnlation and now it shows the correct link as you can see in the attached screenshot.