self-hosted /scrape doesn't populate the JSON schema

[{
"success": true,
"status": "completed",
"completed": 1205,
"total": 1205,
"creditsUsed": 6025,
"expiresAt": "2025-06-12T13:42:40.000Z",
"data": [
  {
    "metadata": {
      "generator": "mkdocs-1.6.1, mkdocs-material-9.6.2+insiders-4.53.15",
      "ahrefs-site-verification": "b13556...60a",
      "favicon": "https://example.com/_images/favicon.ico",
      "viewport": "width=device-width,initial-scale=1",
      "title": "Explore example.com Docs: Your Resource for... ",
      "language": "en",
      "description": "Access example.com Docs for ...",
      "scrapeId": "a01....646",
      "sourceURL": "https://example.com",
      "url": "https://example.com/",
      "statusCode": 200,
      "contentType": "text/html; charset=UTF-8",
      "proxyUsed": "basic"
    }
  }
},...

{
  "main_content": "## FULL MARKDOWN CONTENT",
  "shouldUseSmartscrape": false,
  "smartscrape_reasoning": null,
  "smartscrape_prompt": null
}

{
  "urls": $My_Links_Array,
  "ignoreInvalidURLs": true,
  "formats": [
    "json"
  ],
  "onlyMainContent": true,
  "maxAge": 86400000,
  "waitFor": 1000,
  "jsonOptions": {
    "prompt": "Get all the main content, leaving out any headers, footers, images and menus",
    "schema": {
      "type": "object",
      "properties": {
        "main_content": {
          "type": "string"
        }
      }
    }
  }
}