main.tsx defaultNotFound component is being rendered instead a root pathless route notFoundComponent #6351

Which project does this relate to?

Router

Describe the bug

root pathless notFound is not rendering instead of main.tsx defaultNotFoundComponent is being triggered.

Your Example Website or App

https://github.com/rahulvils/tanstack-router-not-found

Steps to Reproduce the Bug or Issue

1. Clone the repository
2. Run pnpm i
3. Run pnpm dev
4. Open http://localhost:3000 in your browser
5. Click on the Skill Agent button in the home page, You will be redirected to skill-agent page
6. Now manually go the the route to trigger not-found component http://localhost:3000/agents/skill-agen
7. The not-found component in the _authenticated/agents/route.tsx will be triggered (Which is expected)
8. Now go the location in the codebase _authenticated/agents/route.tsx and comment the notFoundComponent
9. Now navigate to the same link http://localhost:3000/agents/skill-age the main.tsx defaultNotFoundComponent is being triggered instead of _authenticated.tsx notFound component

Expected behavior

For root pathless route (say routes/_authenticated.tsx) the notFound component is not being triggered and main.tsx defaultNotFoundComponent is being triggered. I didn't change the default behaviour of notFoundMode (which is fuzzy)

Screenshots or Videos

No response

Platform

• Router Version: 1.147.0
• OS: Linux (Ubuntu 24.04)
• Browser: Chrome
• Browser Version: 143.0.7499.192 (Official Build) (64-bit)
• Bundler: Vite
• Bundler Version: 7.1.1

Additional context

No response