Parent Layout Data is not sent to page when invalidated by `await parent()`

Describe the bug

When a +layout.server.ts load function is re-ran on the server side via await parent(), the data it returns is not sent down to the page.

This should either be considered a bug since the function is called and the data is already calculated, but it is not sent to the page, or there should be some way to manually invalidate it on the server-side (invalidate is client-only).

Note that invalidate does produce the expected result when called from the client.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-xhrebt?file=src/routes/+layout.server.ts

Logs

No response

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 16.14.2 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 7.17.0 - /usr/local/bin/npm
  npmPackages:
    @sveltejs/adapter-auto: ^2.0.0 => 2.0.0 
    @sveltejs/kit: ^1.5.0 => 1.10.0 
    svelte: ^3.54.0 => 3.55.1 
    vite: ^4.0.0 => 4.1.4

Severity

serious, but I can work around it

Additional Information

No response

Start with the StackBlitz reproduction and src/routes/+layout.server.ts, then trace how await parent() reruns the server-side layout load and transfers its data to the page. Verify the behavior with the reported SvelteKit versions; done means the parent layout data is delivered to the page after server-side invalidation without breaking the client-side invalidate behavior.