Does FAQ schema still work?
You added FAQ markup for the extra result space, then the extra result space mostly went away.
The display benefit largely went
Search engines substantially restricted FAQ rich results for most sites. If the expanded snippet was your reason, that reason no longer holds and you should stop expecting it back.
The legibility benefit did not
A question and its direct answer, marked up as such, is precisely the shape systems that summarise want. As more discovery happens through answers rather than links, structured question-and-answer content becomes more useful, not less.
But only if the questions are real
Invent the questions and you have written filler that helps nobody and marks it up as helpful. Take them from People Also Ask, from autocomplete, from your support inbox. Real questions, answered directly, is the whole technique.
What changed and what did not
Google narrowed FAQ rich results sharply, and most sites that had them lost them. The markup did not become invalid and it did not become harmful. It stopped being a reliable way to occupy more vertical space in the result, which was the only reason most sites added it.
Keep it if it is honest, drop it if it is padding
If the page genuinely answers a set of questions, the markup describes it accurately and costs nothing to leave in place. If the questions were invented so the markup would validate, remove them, because you are now maintaining fake content for a feature that no longer displays. That is the entire decision.
Measured, not asserted
Questions on this project's pages are extracted from sections written to answer things people actually asked, not generated to fill a schema block. That constraint is the difference between the technique working and being spam.
Free tool for this: Schema Generator. No account, nothing uploaded.
Where this goes deeper
Every number on this page comes from one complete dataset: one product taken from zero to 100K+ users on search alone, with nothing spent on advertising. The full argument is Chapter 7 and Chapter 12 of the book. Five chapters are free to read.