Migration problems with form-data-parser

[Apsysikal]

Reproduction

I am working on migrating my remix app to react-router and am now stuck on this part: https://remix.run/docs/en/main/start/future-flags#multipart-form-data-and-file-upload-utilities
I've updated my actions to this:

const uploadHandler = async (fileUpload: FileUpload) => {
  let storageKey = getStorageKey("temporary-key");
  await fileStorage.set(storageKey, fileUpload);
  return fileStorage.get(storageKey);
};

const formData = await parseFormData(request, uploadHandler);

This works when i run the dev-server. But when i run a production-build the formData is empty. Does anyone know how this could be happening?
When i do

const formData = await request.formData();

I see the formData is present on the request. After I do that the parseFormData functions complains about the stream being locked.

My vite config looks like this:

import mdx from "@mdx-js/rollup";
import { vitePlugin as remix } from "@remix-run/dev";
import { defineConfig } from "vite";
import tsconfigPaths from "vite-tsconfig-paths";

declare module "@remix-run/server-runtime" {
  // or cloudflare, deno, etc.
  interface Future {
    v3_singleFetch: true;
  }
}

export default defineConfig({
  server: { port: 3000 },
  plugins: [
    mdx(),
    remix({
      future: {
        v3_fetcherPersist: true,
        v3_relativeSplatPath: true,
        v3_throwAbortReason: true,
        v3_singleFetch: true,
        v3_lazyRouteDiscovery: true,
        v3_routeConfig: true,
      },
    }),
    tsconfigPaths(),
  ],
});

My routes config looks like this:

import { flatRoutes } from "@remix-run/fs-routes";

export default flatRoutes();

A route not yet migrated still works:

const formData = await request.formData();

Any guidance would be appreciated

System Info

System:
    OS: Linux 6.5 Debian GNU/Linux 11 (bullseye) 11 (bullseye)
    CPU: (12) arm64 unknown
    Memory: 4.92 GB / 7.66 GB
    Container: Yes
    Shell: 5.1.4 - /bin/bash
  Binaries:
    Node: 20.18.0 - /usr/local/bin/node
    Yarn: 1.22.22 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
    pnpm: 9.12.1 - /usr/local/share/npm-global/bin/pnpm
  npmPackages:
    @remix-run/dev: ^2.15.2 => 2.15.2 
    @remix-run/fs-routes: ^2.15.2 => 2.15.2 
    @remix-run/node: ^2.15.2 => 2.15.2 
    @remix-run/react: ^2.15.2 => 2.15.2 
    @remix-run/route-config: ^2.15.2 => 2.15.2 
    @remix-run/serve: ^2.15.2 => 2.15.2 
    vite: ^6.0.5 => 6.0.7

Used Package Manager

npm

Expected Behavior

Continue working as before migration

Actual Behavior

Breaks in the production build of Vite. The formData is always empty