Extra Fields (JSON) render on an existing page but not on newly created pages

[napaseefog]

Description

Extra fields defined in Settings → Contact Information → "Extra Fields (JSON Object)" render correctly
on a page I created earlier today, but do not render at all on any page created afterwards — even when
the new page is configured with identical settings, section by section.

The same JSON works on the older page and produces nothing on the newer ones. No fields appear at all;
it is not a case of some fields rendering and others not.

Steps to reproduce

1. On an existing page, set Extra Fields to a valid JSON array. Confirm the fields render on the public form.
2. Create a new page.
3. Set Extra Fields on the new page to a single minimal field, before changing any other setting:

   [
     {
       "tag": "textarea",
       "label": "Test"
     }
   ]

4. Save and open the new page's public form.

Expected

The "Test" textarea appears on the new page's public form.

Actual

No extra field appears. The rest of the form (date/time, name, email) renders normally.

What I have already ruled out

• JSON validity — the identical JSON renders correctly on the older page.
• Saving — navigating away from the settings panel and back shows the JSON still present in the box.
• Wrong page/link — the public link is copied from the new page's own settings; the two pages'
  tokens differ. Setting a distinctly labelled test field on the new page does not cause it to appear
  on the old page either, so the settings panel is bound to the correct page.
• Caching — tested with hard reload (Ctrl+Shift+R) and in a private window.
• Page state — the new page is enabled and its public form is otherwise fully functional.
• Configuration drift — I recreated the page a second time, matching the working page's settings
  line by line. Same result.

Log output

With logging at Debug level, loading the new page's public form produces no error from the app.
The only entries from appointments are deprecation notices: