Calling router.refresh after a notFound error does not update the page

Link to the code that reproduces this issue

https://github.com/zoeyfyi-sage/nextjs-notFound-refresh-issue

To Reproduce

1. next dev
2. Note that homepage renders
3. Click toggle on the top right to toggle the visibility of this page, note that page returns 404
4. Click the toggle again, note that the page does not update and the 404 is still displayed

Current vs. Expected behavior

https://github.com/user-attachments/assets/a7617a57-7482-4029-af10-5f0327a88c07

• When the toggle moves from true to false, the page rerenders and a 404 is returned. This is the desired behaviour.
• When the toggle moves from false to true, the page rerenders with the correct true value but the browser remains on the 404 page

Provide environment information

/bin/sh: yarn: command not found
/bin/sh: pnpm: command not found

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 23.6.0: Fri Jul  5 17:55:37 PDT 2024; root:xnu-10063.141.1~2/RELEASE_ARM64_T6030
  Available memory (MB): 36864
  Available CPU cores: 11
Binaries:
  Node: 23.6.0
  npm: 10.9.2
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 15.3.0-canary.5 // Latest available version is detected (15.3.0-canary.5).
  eslint-config-next: N/A
  react: 19.0.0
  react-dom: 19.0.0
  typescript: 5.8.2
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Dynamic Routes, Output, Runtime

Which stage(s) are affected? (Select all that apply)

next dev (local), next start (local)

Additional context

We have the same issue on Next 14, so it is likely a misunderstanding on how notFound and refresh interact.

Start with the reproduction repository linked in the issue, run next dev, and follow the toggle steps to reproduce the 404 state. Trace the interaction between router.refresh and notFound; done means toggling back to the visible state updates the browser from the 404 page while preserving the expected 404 when the page is hidden.