I’d like to add FAQPage json+ld to my website, but i found that the definition for this tag on google examples and schema.org documentation are different:

https://developers.google.com/search/docs/appearance/structured-data/faqpage

<script type="application/ld+json">
    {
      "@context": "https://schema.org",
      "@type": "FAQPage",
      "mainEntity": [{
        "@type": "Question",
        "name": "How to find an apprenticeship?",
        "acceptedAnswer": {
          "@type": "Answer",
          "text": "<p>We provide an official service to search through available apprenticeships. To get started, create an account here, specify the desired region, and your preferences. You will be able to search through all officially registered open apprenticeships.</p>"
        }
      }, {
        "@type": "Question",
        "name": "Whom to contact?",
        "acceptedAnswer": {
          "@type": "Answer",
          "text": "You can contact the apprenticeship office through our official phone hotline above, or with the web-form below. We generally respond to written requests within 7-10 days."
        }
      }]
    }
</script>

The google says that the mainEntity should be an array but the schema.org documentation https://schema.org/FAQPage says that the mainEntity should be a Thing.

Do the google do not follow the schema.org recommendations or the Thing also can be array? If Thing also can be an array is that true for all places where Thing can be used?