Hello @marco2
Thanks for reaching out to us.
preview: false usually disable previews and toolbar on your website. The module won't inject Prismic preview script anymore, and the /preview page won't be registered. It should work.
Are you looking for an API response on your website or your API browser? If your changes appear correctly in the browser but not on the website, then this article covers the most common reasons for this.
Can you also try to remove modern set to true in the nuxt.config.js file?
modern: true
This has been known to cause issues:
Nuxt Generate won't create repeatable type pages Nuxt.js
Give this a try and let me know.
Thanks,
Priyanka