In additon to elisolution's solution above, this also checks whether or not we are literally on the home webpage (not just whether or not the canonical was set or not). I tested this Resolution a little and so far as I can see, it really works as anticipated. Usually, make sure https://addons.prestashop.com/nl/seo-zoekmachineoptimalisatie-vermelding/31857-automatische-google-rich-snippets-json-ld-opengraph-seo.html