Hi,
I have attached a new screenshot of the Simple portal interface where this is entered. The odd thing is that it is displaying correctly for other (non-Google) ads in the same ad locations. This is even true when the vertical dimension of the Google ad is significantly smaller that the other ads.
This is an example of the custom code that I have entered in the Ad Seller Manage Ads tab:
<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<!-- 728x90 -->
<ins class="adsbygoogle"
style="display:inline-block;width:728px;height:90px"
data-ad-client="ca-pub-7278041560049766"
data-ad-slot="5169343783"></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});
</script>