WebHdfs Api successfully CREATES file, but APPEND is apparent failure despite 200 response using HttpClient()

Question

I have a WebHdfs API that successfully CREATES a file, but then when I try to APPEND a byte array of data to the same file I run into issues.

I have no issues creating a file, so I know it is not a permissions or data issue.

1. I run a POST request to the server, receive a 307 response, and then send another POST request to the Header.Location with the data to be appended.
2. The response from the second request is 200, indicating success, and the file I appended to grows larger, seemingly indicating the data was appended successfully.
3. When I try to open the file (parquet) the reader informs me that the amount of rows is equal to the rows that have been appended, but I cannot see the data. This indicates that the APPEND function is not working and the file has been corrupted somehow.
4. I have tested the same operation to a local file using FS and the data is successfully appended and the file is correct.
5. I have also tested sending the data that I want to append in a CREATE operation and this also works, indicating further that the data I send in the APPEND operation is valid.

I expect that the file would grow larger after the append, and I would be able to open the file and see the appended data as well as the original data.

I have also confirmed that "&datanode=true" in the request URI.

At this point I am left to conclude that there might be something wrong with the WebHdfs API.

Has anyone here successfully appended data to a file in the fashion before?

If there are any other ideas please let me know.

uri = _strURI + (strFullFileName + "?op=APPEND&user.name=" + _webHdfsUserName);
method = "POST";

private async Task<bool> RunPutBinaryFileRequest(string strURI, string strMethod, byte[] data)
{
    bool blnResult = false;

    try
    {
        var handler = new HttpClientHandler
        {
            AllowAutoRedirect = false,
            PreAuthenticate = true,
        };
        var hClient = new HttpClient(handler);
        var request = new HttpRequestMessage
        {
            Method = new HttpMethod(strMethod), //PUT or POST: PUT = CREATE , POST REQUIRED FOR APPEND, determined by calling function.
            RequestUri = new Uri(strURI),
        };
        hClient.DefaultRequestHeaders.Referrer = new Uri(strURI);
        hClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes(_webHdfsUserName + ":" + _webHdfsPassword)));

        var response = await hClient.SendAsync(request);
        //response.EnsureSuccessStatusCode();
        blnResult = await UseBinaryHTTP(data, response.Headers.Location, strMethod);
        hClient.Dispose();
    }
    catch (HttpRequestException ex)
    {
        _logger.LogError("[RunBinaryPutFileRequest]request}::WebException{ex}", ex.Message);
    }
    return blnResult;
}

private async Task<bool> UseBinaryHTTP(byte[] data, Uri url, string strMethod)
{
    var success = false;
    try
    {
        var hClient = new HttpClient();
        var sContent = new ByteArrayContent(data);
        var aValue = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes(_webHdfsUserName + ":" + _webHdfsPassword)));
        hClient.DefaultRequestHeaders.Authorization = aValue;
        var request = new HttpRequestMessage
        {
            Method = new HttpMethod(strMethod),
            RequestUri = url,
            Content = sContent
        };
        request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
        var response = await hClient.SendAsync(request);

        response.EnsureSuccessStatusCode();
        hClient.Dispose();
        success = true;
    }
    catch (HttpRequestException ex)
    {
        _logger.LogError("[UseBinaryHTTP]request}::WebException{ex}", ex.Message);
    }
    return success; 
}