[bug] Static Front Page 404

I know you are super duper busy Joost ?? But maybe you could find a few minutes to take a look at this bug:

<link rel=amphtml href="https://domain.com/amp/"/>

is present in head but the /amp/ link results in a 404.

https://www.ads-software.com/plugins/glue-for-yoast-seo-amp/