Welcome back.

Just to add to your comments on AMP. Even though the WordPress plugin is great and makes the process easier, you can still fail validation for a lot of reasons such as plugins.

There is another plugin that helps in this regard. You can find it at https://wordpress.org/plugins/pagefrog/. This plugin helped to fix all but 1 of my issues. It does allow some basic styling options.

The last problem I had was caused by the Scrapeshield feature of Cloudflare. I turned it off and my pages became AMP compliant.