Google ads display at strange places

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=""></script>
     <ins class="adsbygoogle"
       (adsbygoogle = window.adsbygoogle || []).push({});


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?