XML upload adds ZWNBSP to beginning of file

var sessionOptions = new SessionOptions
{
    Protocol = Protocol.Sftp,
    HostName = ulbcFtpHost,
    UserName = ulbcFtpUser,
    Password = ulbcFtpPassword,
    SshHostKeyPolicy = SshHostKeyPolicy.GiveUpSecurityAndAcceptAny
};
 
using (var session = new Session())
{
    session.Open(sessionOptions);
    foreach (FileInfo file in files)
    {
        var hasError = false;
        try
        {
            // upload the file
            TransferOptions transferOptions = new TransferOptions
            {
                TransferMode = TransferMode.Binary                                
            };
 
            Stream stream = new FileStream(file.FullName, FileMode.Open);
 
            session.PutFile(stream, $"{ulbcFtpPath}/{file.Name}", transferOptions);
 
            stream.Close();
 
            Logger($"File {file.Name} uploaded successfully to SFTP server.");
        }
        catch (Exception ex)
        {
            hasError = true;
            Logger($"Error uploading file: {ex.Message}");
        }
 
        if (!hasError)
        {
            // archive the file
            try
            {
                if (!Directory.Exists(ulbcArchivePath))
                {
                    Directory.CreateDirectory(ulbcArchivePath);
                }
                var destinationPath = Path.Combine(ulbcArchivePath, file.Name);
                if (File.Exists(destinationPath))
                    File.Delete(destinationPath);
                File.Move(file.FullName, destinationPath);
                Logger($"File archived: {file.Name}");
            }
            catch (Exception ex)
            {
                Logger($"Unable to archive file {file.Name}. {ex.Message}");
            }
        }
    }
}