N parallel routes rendered N² times

[MariusNWK]

Summary

Hello,

I'm having an issue with parallel routes deployed on Vercel.

I reproduced the error inside a sandbox project that I will use for explanations.

I use parallel routes on the parallel page: src/app/parallel

Here is a screen of what's inside:

Here is the .zip of what's inside:
parallel.zip

Here is the content of src/app/parallel/layout.tsx:

Here is the content of src/app/parallel/page.tsx:

Here is the content of src/app/parallel/StatSelector.tsx:

Here is the content of src/app/parallel/@user/page.tsx:

loading.tsx files just contain a component that returns <div>loading</div>

error.tsx files just contain a component that returns <div>error</div> (+ "use client")

src/app/parallel/@approach/page.tsx & src/app/parallel/@instance/page.tsx are similar with console.log & <div> content adapted

Here is the content of src/app/parallel/getData.ts:

I don't have any weird behaviors in yarn dev or yarn build && yarn start in local.

But when I deploy my app on Vercel, n pages are loaded n² times.

As you can see, I added console.log inside each page.tsx.

When I access /parallel page, I have the expected behavior:

Every console.log is displayed once.

Now when I access /parallel?take=15, I don't have the expected behavior:

Each page.tsx are loaded 4 times.

This is for my sandbox app, but for my "real" app I have more than 30 parallel routes, and when I access the page without seachParams, I also have the issue.
I use parallel routes for a stats page /stats/cityHall, each parallel route needs 1 db call so the expected behavior should be to have 30 db calls but I currently have 30x30 = 900 db calls (makes my database crash).

I can't find what I'm doing wrong. Do you know what didn't I understand ?

Any help would be very much appreciated.

Many thanks in advance !

Additional information

No response

Example

No response

[icyJoseph]

Hi, could you try to set this up in a repository, or stackblitz? The prisma stuff can be removed, just make it fetch uuids from http://httpbin.dev/uuid

[MariusNWK]

Hello, thank you for your answer, I created an issue here : #81416
The bug is reproduced without db call inside the public repository I shared inside the issue