UpdateTag is causing hard refresh

[lucas-garrido]

Link to the code that reproduces this issue

https://github.com/lucas-garrido/nextjs-issue-reproduction

To Reproduce

I'm using parallel routes modals

1. Start the application
2. Go to /test url
3. Open the first Modal => Go to detail page => Open second modal => Click on update tag button

Current vs. Expected behavior

The updateTag is causing hard refresh ending to a 404 error page.
This issue is related to the navigation flow if i start the app directly on the detail page (/test/42) the updateTag is working as expected

Provide environment information

Operating System:
  Platform: linux
  Arch: x64
  Version: #50~22.04.1-Ubuntu SMP Wed Dec  3 15:13:22 UTC 2025
  Available memory (MB): 7944
  Available CPU cores: 2
Binaries:
  Node: 24.14.0
  npm: 11.9.0
  Yarn: 1.22.22
  pnpm: 10.32.1
Relevant Packages:
  next: 16.2.4 // Latest available version is detected (16.2.4).
  eslint-config-next: N/A
  react: 19.2.4
  react-dom: 19.2.4
  typescript: 5.9.3
Next.js Config:
  output: N/A

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

Parallel & Intercepting Routes, Server Actions

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

next dev (local), next start (local)

Additional context

No response

[nehaaprasaad]

Hello! @lucas-garrido please check out the PR, thankyou!