Razor Page Large File Upload resulting in 400 Bad Request

I have a razor page for uploading files. I've set the maximum upload size to 4GB, but when I upload something larger than 2 GB I get an 400 Bad Request Error. I've added everything I found on the internet, that might help with the maximum upload size. At one point I thought the error was gone, but then it came back, with nothing changed in the code.
The Website is hosted on an IIS.

Has someone a hint what it might be? I'll include all upload size related code I've got.

Sidenote: When I upload a file > 2GB but < 4GB i get an 400 Bad Request Error.
When I upload a file larger than 4GB I get an 413 Request Entity Too Large Error.

I have these settings in my program.cs:

builder.Services.Configure<FormOptions>(o =>
{
    o.ValueLengthLimit = int.MaxValue;
    o.MultipartBodyLengthLimit = int.MaxValue;
    o.MultipartBoundaryLengthLimit = int.MaxValue;
    o.MultipartHeadersCountLimit = int.MaxValue;
    o.MultipartHeadersLengthLimit = int.MaxValue;
    o.BufferBodyLengthLimit = int.MaxValue;
    o.BufferBody = true;
    o.ValueCountLimit = int.MaxValue;
});

builder.Services.Configure<IISServerOptions>(options =>
{
    options.MaxRequestBodySize = int.MaxValue;
});

builder.Services.Configure<KestrelServerOptions>(options =>
{
    options.Limits.MaxRequestBodySize = int.MaxValue;
});

builder.WebHost.ConfigureKestrel(c =>
{
    c.Limits.KeepAliveTimeout = TimeSpan.FromMinutes(100);
});

These settings in my web.config:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.web>
    <!-- ~ 2GB -->
    <httpRuntime maxRequestLength="419430412" executionTimeout="3600" /> // kbytes
    <globalization 
           requestEncoding="utf-8"
           responseEncoding="utf-8"
        />
  </system.web>
  <system.webServer>
    <security>
      <requestFiltering>
        <!-- ~ 4GB -->
        <requestLimits maxAllowedContentLength="4294967295" /> // bytes
      </requestFiltering>
    </security>
  </system.webServer>
</configuration>

And this is the upload code:

	[HttpPost]
    [RequestFormLimits(MultipartBodyLengthLimit = 4294967295)]
    [RequestSizeLimit(4294967295)]
    public async Task<IActionResult> OnPostAsync()
    {
        var files = Request.Form.Files;

        // Für Progress Bar
        var uploads = Path.Combine(_environment.WebRootPath, "uploads");
        var totalBytes = files.Sum(f => f.Length);

        //long bytesUploaded = 0;
        //var progressHandler = new ProgressHandler(_httpContextAccessor);

        // Folder Name 
        var folderName = DateTime.Now.ToString("yyyy-MM-dd-HHmmss") + " - " + HttpContext.Session.GetString("selectedResp");
        var folderPath = Path.Combine(@"C:\UploadTool\Uploads", folderName);

        if (!Directory.Exists(folderPath))
        {
            Directory.CreateDirectory(folderPath);

            if (files.Count == 0)
            {
                return BadRequest("No files selected.");
            }

            foreach (var file in files)
            {
                var filePath = Path.Combine(folderPath, file.FileName);
                using (var stream = new FileStream(filePath, FileMode.Create))
                {
                    await file.CopyToAsync(stream);
                }
            }

        } 
        else
        {
            //ModelState.AddModelError(string.Empty, "Folder already exists!");
        }

        return RedirectToPage("Upload");
    }

This fixed the problem. Thanks to @pcalkins

builder.Services.Configure<FormOptions>(o =>
{
    o.ValueLengthLimit = int.MaxValue;
    o.MultipartBodyLengthLimit = 4L * 1024L * 1024L * 1024L;
    o.MultipartBoundaryLengthLimit = int.MaxValue;
    o.MultipartHeadersCountLimit = int.MaxValue;
    o.MultipartHeadersLengthLimit = int.MaxValue;
    o.BufferBodyLengthLimit = 4L * 1024L * 1024L * 1024L;
    o.BufferBody = true;
    o.ValueCountLimit = int.MaxValue;
});

builder.Services.Configure<IISServerOptions>(options =>
{
    options.MaxRequestBodySize = Int64.MaxValue;
});

builder.Services.Configure<KestrelServerOptions>(options =>
{
    options.Limits.MaxRequestBodySize = Int64.MaxValue;
});