Okay, I’ve figured it out by myself. It is because of a missing plural translation for following translation string in de_DE (formal and non-formal)
36122 #: includes/admin/class-wc-admin-setup-wizard.php:511
36123 #: includes/wc-account-functions.php:102
36124 #: packages/woocommerce-blocks/src/StoreApi/Schemas/V1/AbstractAddressSchema.php:37
36125 #: packages/woocommerce-blocks/src/StoreApi/Utilities/OrderController.php:330
36126 #: assets/client/admin/app/index.js:2
36127 #: packages/woocommerce-blocks/build/wc-settings.js:1
36128 msgid "Address"
36129 msgid_plural "Addresses"
36130 msgstr[0] "Adresse"
36131 msgstr[1] ""
Maybe someone could make an update on the language translation files and add the proper plural translation for msgid “Address”. I’ve changed it as follows:
36131 msgstr[1] "Adressen"
This should solve the problem for many German users.
