Directly under the existing site
I created a child site but it is not indexed. Is this possible?

Error message

I've been starting about a month ago.
Even if you enter the official name, it will not be indexed.
I thought it was funny
If i try with "site: address"
"No matching information was found."
"Prevent search engines from indexing my site" is not checked.
The search console has also been registered for about a week, but the accumulated data remains zero.

What you care about and what you can think of

One thing I'm interested in is the "structure" of the site I am currently making.

The site I'm making this time is
This is a group site created directly under the parent site "Sample.com".
(Sample.com/hutatume, feel like)

Sample.com is properly indexed.
site: Sample.com/hutatume
When it becomes, it becomes "it doesn't agree".

Is there anything related to linking (parent-child relationship) with existing sites?
Does it matter?

By the way, we have not yet linked from the parent site etc. (coming soon, so we will have a banner on the parent site this week)

Supplemental information (FW/tool version etc.)

wordpress5.3