Hello, Gianluca,
Please clear all cache and check now.
Pages create using Elementor, for example, Contact us, show not amp version: https://www.8theme.com/documentation/xstore/amp-plugin/general-info-amp/ –
“Because AMP uses minimal code for quick loading, it can’t include all the elements on a fully functioning webpage, such as certain widgets, embedded content, or pages created using page builders (Elementor/WPBakery). This means that a webpage viewed with AMP looks like a mobile application to facilitate the user experience and doesn’t look exactly the same as how the original page would appear on a desktop or laptop.”
Kind Regards,
8theme team