Very large (500mb+) file request body null

[mrxbox98]

Describe the bug

The event.request.body on requests where the body is 500mb+ appears as null, even with a BODY_SIZE_LIMIT of 10gb or Infinity. I am currently trying to upload a large file using

let req = await fetch("/api/upload", {
    method: "POST",
    headers: {
        filename: file.name,
    },
    body: file,
    
});

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-uhls8v?file=src%2Froutes%2F%2Bpage.svelte

Try uploading a file ~1gb in size, it will have a reqest.body of null. Uploading a file at 504mb works for me.

Logs

No response

System Info

System:
    OS: Windows 11 10.0.22631
    CPU: (16) x64 AMD Ryzen 9 5900HX with Radeon Graphics
    Memory: 4.86 GB / 31.42 GB
  Binaries:
    Node: 20.9.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.19 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 9.6.7 - C:\Program Files\nodejs\npm.CMD
    pnpm: 8.8.0 - ~\AppData\Local\pnpm\pnpm.EXE
    bun: 1.1.21 - ~\.bun\bin\bun.EXE
  Browsers:
    Edge: Chromium (127.0.2651.74)
    Internet Explorer: 11.0.22621.3527
  npmPackages:
    @sveltejs/adapter-auto: ^3.0.0 => 3.2.4
    @sveltejs/adapter-node: ^5.2.2 => 5.2.2
    @sveltejs/kit: ^2.5.24 => 2.5.24
    @sveltejs/vite-plugin-svelte: ^3.1.2 => 3.1.2
    svelte: ^4.2.19 => 4.2.19
    vite: ^5.4.2 => 5.4.2

Severity

serious, but I can work around it

Additional Information

No response