FAQPage vs QAPage
Use FAQPage when one author wrote both questions and answers (like this page). Use QAPage when users post questions and others answer (forums, Q&A communities). They're not interchangeable.
Every Q must have exactly one accepted A
Multiple acceptedAnswer entries break the schema. Use suggestedAnswer for additional perspectives.
Mark up only visible content
Schema for hidden text is a guidelines violation. Every Q&A in your JSON-LD must be visible to users on the page.
Test with the Rich Results Test
search.google.com/test/rich-results — it shows exactly what Google sees and flags errors before you deploy.