Code samples not showing, `generateCodeSamples` has no effect

[KieranP]

Just installed Redoc CLI 2.0.8. Added the following to redocly.yaml based on https://github.com/Redocly/openapi-starter/blob/main/redocly.yaml:

openapi:
  hideDownloadButtons: true
  generateCodeSamples:
    languages:
      - lang: curl
      - lang: Node.js
      - lang: JavaScript
      - lang: PHP
      - lang: Python

Generate the site and the download buttons are gone, but no code samples found anywhere...

What am I missing?