Description

Content doesn't update when previewing a draft when that draft was previously public.

Step-by-step reproduction instructions

1. Open the edit page for a brand new post
2. Add "Title" as title and hit "Publish"
3. Hit preview in a new tab
4. Notice the preview works great
5. Update the title to "Autosaved Title" and preview
6. Notice preview still works great
7. Reload the page (without explicitly saving)
8. Notice the title is correctly "Title"
9. Hit preview in a new tab
10. Notice the title is incorrectly "Autosaved Title"

Expected behaviour

The Title in the preview to be the current title in the editor

Actual behaviour

The Title in the preview is wrong, an older autosaved title

WordPress information

• WordPress version: 5.8
• Gutenberg version: Whatever ships with WP 5.8
• Are all plugins except Gutenberg deactivated? Yes
• Are you using a default theme (e.g. Twenty Twenty-One)? Yes

Device information

• Device: Desktop
• Operating system: macOs 11.4
• Browser: Chrome 91.0.4472.164