WPML problem: Wrong URL slug languages in file

Hi, thanks for the clear report and the before/after URLs.

When the file is generated, we ask WordPress for the post’s permalink and then hand it to WPML’s wpml_permalink filter to apply the correct language. What your example (/en/kontakt/ instead of /en/contact/) suggests is that we’re getting the permalink back in the default language’s slug (kontakt) and WPML is only adding the /en/ language prefix on top, rather than swapping in the translated slug. That would produce the mixed result you’re seeing, and it would explain why an otherwise-identical site behaves differently . It comes down to how each site’s slugs and language URLs are configured.

We don’t run a WPML license on our side (it’s a paid plugin and there’s no free build to test against), so your setup is the only window I have into this:

1. In WPML → Languages → Language URL format, which option is selected — “Different languages in directories,” a subdomain/parameter, or different domains?
2. For that Contact page specifically: when you edit the English translation, is its slug actually set to contact in the editor, or has it been left as kontakt? (WPML keeps a separate slug per translation, and it’s easy for it to inherit the original.)

If you can also tell me whether the URLs are correct when you visit the English pages normally on the front end (i.e. does the browser show /en/contact/?), that tells me whether the problem is only in our file or in the permalink WordPress itself is returning.

Once I know those, I can put together a fix and share a test build for you to confirm against your live setup before it ships.