Google ads display at strange places

Developer help
1

I’ve set up a self hosted Ghost server. The site is Google Adsense approved. I tried adding “Matched content” (a block of adds with both links to other parts of my site and ads). So far so good. I add it in post.hbs at the post.-content-comments section:

<section class="post-content-comments">

   <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
     <ins class="adsbygoogle"
       style="display:block"
       data-ad-format="autorelaxed"
       data-ad-client="ca-pub-xxxxxxxxxxxx"
       data-ad-slot="xxxxxxxxxx"></ins>
     <script>
       (adsbygoogle = window.adsbygoogle || []).push({});
     </script>

</section>

The bottom section looks fine. But for some reason it displays a huge ad on the very top (!) of the page. Somewhere around the header. Messing up the whole design. Is this a Ghost issue or is it a Google Adsense issue, in which case, do you know how to make it not do that?