Duplicate Requests in Next.js 14 on Server Side with Parallel Routes and Intercepting Routes

[Semmy99]

Link to the code that reproduces this issue

https://codesandbox.io/p/devbox/nextjs-test-forked-rrpt2x?file=%2Fpackage.json%3A12%2C4-14%2C23

To Reproduce

1. Set up a Next.js 14 project.
2. Create a use server component that makes a request.
3. Use parallel routes and intercepting routes in your application.
4. Run the application in development mode (npm run dev).
5. Observe duplicate requests being made.

Additional details from discussion:

• When using the @modal folder, the issue occurs. Removing the @modal folder resolves the issue.

example

Current vs. Expected behavior

Current Behavior:
Requests in use server components are being duplicated when using parallel routes and intercepting routes in development mode.

Expected Behavior:
Requests should only be made once, avoiding duplicates.

Provide environment information

winwos 10,
node v20.11.1,
next "14.2.1",
react "^18",
react-dom "^18"

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

Developer Experience, Parallel & Intercepting Routes

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

next dev (local), next build (local), next start (local)

Additional context

I have encountered an issue where requests in use server components are being duplicated when using parallel routes and intercepting routes in Next.js 14. If I remove the @modal folder, the problem disappears. This suggests a bug related to parallel routes and intercepting routes in Next.js.

Example discussion link: #66384

Steps to resolve suggested in the discussion, such as running in production mode, did not fix the issue.