Broken code snippets on Kirigami - FormCard About pages

There are two code blocks on "Kirigami - FormCard About pages" https://develop.kde.org/docs/getting-started/kirigami/addons-about/ , that display "Not Found" HTML template code instead of actual code snippets.

Snippets in question:

{{< snippet repo="libraries/kirigami-addons" file="examples/FormCardTutorial/contents/ui/MyAboutPage.qml" lang="cpp" >}}
{{< snippet repo="libraries/kirigami-addons" file="examples/FormCardTutorial/contents/ui/JsonAboutPage.qml" lang="cpp" >}}

Maybe an issue with "extract-plasma-applet-config-keys.py" script, as many files in files/libraries/kirigami-addons/examples/FormCardTutorial/ directory have the same "Not Found" content instead of expected file content. But few files actually have correct content, and that makes the issue even more strange.