Background of the issue:
I am experiencing a critical issue with how WPML handles slugs for translated categories. When translating a category from the default language (English) to other languages, WPML automatically appends language-specific suffixes like -pl, -de, -fr to the slug. This slug modification breaks the URL architecture and causes significant problems, especially since many of these categories have unique names (e.g., Porsche, Mercedes, Volvo). The issue affects all translated categories, regardless of language.
Symptoms:
WPML changes the slug of translated categories by appending language-specific suffixes, disrupting the URL structure.
Questions:
Why does WPML add language-specific suffixes like -pl, -de, -fr to the slugs, even when the category names are unique?
How can I configure WPML so that translated categories retain the same slug as the default language without any modifications?
By default WPML adds that language code to the translated slug, as you've noted. However, by following the above mention you can make it either available for translation in the translation editor or copy from original if translation languages uses encoded URLs.