Overriding a page title by the "Title" constant does not work

[takepon-jp]

Overriding a page title by the "Title" constant does not work

Detailed description

Describe in detail the issue you’re having.

The title text displayed on the page header area cannot be overriden even by exporting the "Title" constant in mdx file.
Until the version 3.x, this worked fine. But in the version 4.x, it looks "Title" variable is not propagated into the Layouts/Default layout component.

What did you expect to happen? What happened instead? What would you like to see changed?

The title text on the page header area is overriden by the value of "Title" constant in the mdx file.

What browser are you working in?

Google Chrome 131

Steps to reproduce the issue

1. create a mdx file
2. define the "Title" constant to override the page title. Ex. export const Title = () => <span>This is override title!</span>
3. build
4. check the page on the web browser

Additional information

• Screenshots or code
• Notes