Any time you add hreflang tags, guarantee they all position to indexable and crawlable pages. Verify which tags are causing the problems and rectify them by ensuring that the pages they’re pointing to are Stay.  Canonical URLs are used to avoid duplicate articles and reveal to search engines like google https://addons.prestashop.com/ru/seo-natural-search-engine-optimization/31857--rich-snippets-json-ld-opengraph-seo.html