Whenever you include hreflang tags, make certain they all level to indexable and crawlable pages. Check out which tags are causing the problems and rectify them by making certain the pages they’re pointing to are live.  HubSpot CMS consumers can modify their configurations to contain the CMS automatically add self-referencing https://addons.prestashop.com/it/seo-indicizzazione-naturale/31857-google-rich-snippet-automatico-json-ld-open-graph-seo.html