Query Block won't render when placed in 404 Template

[annezazu]

Description

When adding a Query Block to the 404 template, it doesn't show up on the front end of the site. I tried moving it around to different parts of the template but it simply won't render.

Step-by-step reproduction instructions

1. Setup a site with FSE and TT1 blocks
2. Open the Site Editor.
3. Use the Navigation component to go to the 404 template.
4. Add a query block into the 404 template.
5. Save changes and view the 404 page.

Expected behaviour

I expect to see the Query block results appear.

Actual behaviour

The Query block doesn't not show up on the front end.

Screenshots or screen recording (optional)

missing.query.block.mov

Front end:

Editor:

WordPress information

• WordPress version: 5.7
• Gutenberg version: 10.4.0-rc.1
• Are all plugins except Gutenberg deactivated? Yes
• Are you using a default theme (e.g. Twenty Twenty-One)? TT1 Blocks

Device information

• Device: Desktop
• Operating system: MacOS
• Browser: Chrome v 89

[ntsekouras]

It has to do with context detection and previews. If we have a Query block with inherit:true to a 404 will not have any posts to output from the loop. If we do set inherit:false , Query will have output.

Related: #30369

[mtias]

Also something we could do is add some more text when the setting is toggled on describing that it's reading from the current template, and what that template is.

[annezazu]

I am going to close this out since it seems as though this is covered in the issue around context detection and it seems wise to consolidate currently.