title: Next.js v10 Internalisation - getStaticProps always return default locale
body: <p>I'm trying to setup a new Next.js version project with internalisation based on <a href="https://nextjs.org/docs/advanced-features/i18n-routing#domain-routing" rel="nofollow noreferrer">domain routing</a>.</p>
  <p>I have my <code>next.config.js</code> with the following lines:</p>
  <pre><code>  i18n: {
      locales: ['de-DE', 'en-US'],
      defaultLocale: 'en-US',
      domains: [
        {
          domain: 'mydomain.com',
          defaultLocale: 'en-US'
        },
        {
          domain: 'mydomain.de',
          defaultLocale: 'de-DE'
        }
      ],
      localeDetection: false
    },
  </code></pre>
  <p>and I have my catch-all-routes page like this:</p>
  <pre><code>import React, { Fragment } from 'react';
  
  import * as api from '../api';
  import Header from '../components/Header';
  import Footer from '../components/Footer';
  import Sections from '../components/Sections';
  
  function Page({ page = {} }) {
    return (
      &lt;Fragment&gt;
        &lt;Header /&gt;
        &lt;Sections {...page} /&gt;
        &lt;Footer /&gt;
      &lt;/Fragment&gt;
    );
  }
  
  export async function getStaticProps(context = {}) {
    const { params = {}, locale } = context;
    const pathname = params.slug ? params.slug.join('/') : '/';
    const page = await api.fetchPage(pathname, locale);
  
    return {
      props: {
        page
      },
      revalidate: 1
    }
  }
  
  export async function getStaticPaths() {
    // this will be generated, hardcoded this pages for testing
    return {
      paths: [
        {
          params: {
            slug: ['produkte']
          },
          locale: 'de-DE'
        },
        {
          params: {
            slug: []
          },
          locale: 'de-DE'
        },
        {
          params: {
            slug: ['products']
          },
          locale: 'en-US'
        },
        {
          params: {
            slug: []
          },
          locale: 'en-US'
        }
      ],
      fallback: true
    };
  }
  </code></pre>
  <p>However everytime when I'm trying to preview locally the German version, it returns me English one and I see that inside <code>getStaticProps</code> the value of locale is always <code>en-US</code>. I'm trying to access the page with <code>http://localhost:3000/?__nextLocale=de-DE</code> as an url.</p>
  <p>What's missing here to make it work properly?</p>
  <p>Thanks!</p>