Just tested it in Dutch ("Welkom terug"), which does not trigger the autocomplete.
Is the Safari UI in Dutch for you? (I never set UI language to Dutch if I can avoid it even though it's my native language, the localization is often so clunky that I find it distracting)
I tested it with my native language (both the text on the website and the browser UI). The autofill interface did not show up.
Then again Finnish has anyway been a second class citizen when it comes to iOS features.