Bug: Inconsistent data-sharing between +layout.server.ts and +layout.ts if route does not exist

In the root +layout.server.ts the load is defined like this:

import type { LayoutServerLoad } from './$types';

export const load: LayoutServerLoad = () => {
    return { year: 2024 };
};

And the in the root +layout.ts the load is defined like this and ssr is set to false (important!):

import type { LayoutLoad } from './$types';

export const ssr = false;

export const load: LayoutLoad = ({ data }) => {
    return { year: data.year };
};

When going to a route that exists data contains the expected year property. But when going to a route that does not exist data is suddenly null.

This does not happen if ssr is set to true.

So to summarize:

If route exists

• Receives data from LayoutServerLoad if ssr is true ✅
• Receives data from LayoutServerLoad if ssr is false ✅

If route does not exist

• Receives data from LayoutServerLoad if ssr is true ✅
• Does not receive data from LayoutServerLoad if ssr is false ❌