Possibly your canonical tags are set up incorrectly or Google has decided on to ignore the specified canonical. Major Contentful Paint is some time it will take to load The one most significant visible component in the viewport, and it is a CWV metric Google utilizes. A number of pages https://www.presta-addons-modules.com/en/seo/prestashop-seo-automatic-google-rich-snippets-json-ld-opengraph-twitter-tags-schemaorg.html