parent load function doesn't rerun

Describe the bug

https://svelte.dev/docs/kit/load#Rerunning-load-functions-Manual-invalidation stands:
"A child load function calls await parent() and is rerunning, and the parent is a server load function"
but in this example
1)I have load function in +layout.js in blob. It depends on "some:label" and has "await parent()"
2)I have "+layout.server.js" in root
3)Call invalidate("some:label") reruns load function in blog, but not root server load.
Why?

Reproduction

https://codesandbox.io/p/devbox/my8q4j
run app
click on "to blog"
open server and browser console
click invalidate
in server console no "root layout server load" message
it means that root server load doesn't rerun.

Logs

System Info

System:
    OS: Linux 6.1 Debian GNU/Linux 12 (bookworm) 12 (bookworm)
    CPU: (2) x64 AMD EPYC
    Memory: 2.17 GB / 4.01 GB
    Container: Yes
    Shell: Unknown
  Binaries:
    Node: 20.12.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.5.0 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/share/npm-global/bin/pnpm
  npmPackages:
    @sveltejs/adapter-auto: ^6 => 6.1.0 
    @sveltejs/kit: ^2 => 2.37.0 
    @sveltejs/vite-plugin-svelte: ^5 => 5.1.1 
    svelte: ^5 => 5.38.6 
    vite: ^6 => 6.3.5

Severity

annoyance

Additional Information

No response

Start with the linked manual invalidation documentation and run the CodeSandbox reproduction. Trace the root +layout.server.js load, the blog +layout.js load, and invalidate("some:label") to compare the documented and observed rerun behavior. Done means the behavior is explained and the implementation or documentation is aligned with the intended semantics.