Problem validating faq rich snippets

Hi here’s my problem.
I use the YoothemePro builder and they use their own instance of the TinyMCE editor so I created from an article with Gutenberg the faq through the function you offer and took the html code you see here:

<div class="wp-block-rank-math-faq-block"><div class="rank-math-faq-item"><h3 class="rank-math-question">title faq 1</h3><div class="rank-math-answer">text answer 1.</div></div><div class="rank-math-faq-item"><h3 class="rank-math-question">title fa 2</h3><div class="rank-math-answer">text answer 2.</div></div></div>

and I inserted it into the yootheme builder as an html element
If I go to check with the google tool, however, the rich nisppets from schema.org relating to faq are not “seen”.
Where do I go wrong?

thanks a lot

stefano