404 NOT_FOUND on subdirectories with correct setup

Hello team,

I am facing a persistent 404: NOT_FOUND error on a deployment, and I've exhausted all standard troubleshooting steps.

My project is a monorepo containing multiple static sites and a serverless function. I have confirmed the following:

My GitHub repository has a correct flat file structure with my main index.html, assets, and artist folders all at the root.
My Vercel project settings have the "Root Directory" set to empty.
The "Framework Preset" is correctly set to "Other".
I have a valid package.json and have tried deploying with and without a vercel.json file, but the result is the same: the root index.html loads, but all subdirectory routes (e.g., /luther/, /ajna/) and some assets result in a 404.

This seems to be an internal routing bug on the platform.

GitHub Repository: https://github.com/Nibiru82/hub-artistes
Vercel Deployment URL: https://hub-artistes.vercel.app
A recent Deployment ID: fra1:b1z6p-1751349276062-7bb35c901cf1

Could someone from the Vercel team or the community please take a look? Thank you.

There's another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes.

https://community.vercel.com/t/debugging-404-errors/437

vercel.com

How to debug 404 errors | Vercel Knowledge Base

Learn the systematic steps to identify and resolve 404 issues.

A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.

Hi , welcome to the Vercel Community!

Thanks for sharing the repository and explain the issue. Can you share what the build output is for the deployment you shared? It would reveal the name of files and routes created as a result.

Other than that I noticed that the file names for the subdirectories doesn't match the link that is opened upon clicking the cards (it should just be index.html).

Folder structure