Start: route masks with unmaskOnReload lose the real route on hard reload

[tmm]

Which project does this relate to?

Start

Describe the bug

When a route mask uses unmaskOnReload: true, client navigation works, but a hard reload in TanStack Start SSR keeps the browser on the masked URL.

In the repro, the real route is still present in window.history.state.__tempLocation, but the server renders /. Hydration then lands on / instead of /modal, so the modal route disappears.

Your Example Website or App

https://github.com/tmm/tanstack-mask-reload-repro

Steps to Reproduce the Bug or Issue

1. Open /
2. Click Open masked modal
3. Confirm the modal opens while the URL still shows /
4. Hard reload the page

Expected behavior

After reload, the router should restore /modal before hydration and keep the modal rendered.

Screenshots or Videos

No response.

Platform

• Router / Start Version: @tanstack/react-router 1.168.10, @tanstack/react-start 1.167.16
• OS: macOS
• Browser: Chrome
• Browser Version: current stable
• Bundler: Vite
• Bundler Version: 7.3.2

Additional context

Client navigation behaves correctly. This seems specific to SSR reloads with unmaskOnReload: true.