According to the schema documentation: “A QAPage is a WebPage focused on a specific Question and its Answer(s)”
It isn’t applicable for our plugin, as the page lists multiple questions, each with only one answer, not one question with multiple answers.
There is an alternative parent schema that can be used, called “WebPage” (https://schema.org/WebPage), but that is something that we don’t include directly in the FAQ output because there’s a high chance that either your theme is already including that schema or that another plugin that you have activated would be including that schema.
It looks like they do have that pending schema called FAQPage (https://pending.schema.org/FAQPage), which will be more in line with what we’d want to include in our FAQ Output. Once that is released, we can look into implementing it.
In the meantime, if you want to avoid seeing that message in your testing tool, I’d suggest just adding that WebPage markup to your theme page template.