Loader data not inherited by new dynamic child routes in SvelteKit 2.x

[jst20terrell]

New child routes (folders) created under a dynamic parent ([levelId]) do not inherit loader data from the parent's +layout.js. Existing child routes (created before the issue appeared) continue to work and show the heading as expected.

Duplicating a working child route (scan → scan2) also results in the loader data not being inherited—parent loader is not run for new child routes.

There are no shadowing loaders or layouts in the child routes. Loader logic and structure are correct.

Console logs confirm that the loader is never run for new child routes, but still runs for existing siblings. There are no errors or warnings in the console or build output.

Full clean and rebuild (delete .svelte-kit, .vite, node_modules, lock files, cache, server reboot, move parent folder out and back in, even entire project clone) does NOT resolve the issue. This happens with the latest SvelteKit 2.22.0+ and Vite 7.x, and is not related to legacy migration.

Using SvelteKit: 2.22.0 (also tested 2.25.1, same result)
Node: v20.13.1
Browser: Edge
Computer Windows 11 Pro 64.
Server: Digital Ocean Linux

Reproduction: 1. Project structure:

• /src/routes/(app)/+layout.svelte (global layout displays {data.heading} from loader)
• /src/routes/(app)/levels/[levelId]/+layout.js (returns { heading } and shared loader data for all children)
• /src/routes/(app)/levels/[levelId]/scan/+page.svelte (works: inherits heading)
• /src/routes/(app)/levels/[levelId]/testchild1/+page.svelte (new: does NOT inherit heading, loader not run)

2. Steps:
   a. Add new child folder (e.g., testchild1) under /levels/[levelId]/
   b. Add minimal +page.svelte
   c. Start dev or prod server, visit /levels/1/testchild1

3. Result: Pill bar and child content render, but heading from parent loader is missing (data.heading is undefined). Existing children still work.

Logs: No errors or warnings in terminal or browser. Console.log inside [levelId]/+layout.js confirms loader is never called for new routes.

[brunnerh]

Should this have been an issue?