Chrome. Asp.net/PushStreamContent. Why does video streaming stop?

Question

ASP.NET

API:

public HttpResponseMessage Get(string id)
        {
            var video = new VideoStream(id);
            var response = Request.CreateResponse();
            response.Content = new PushStreamContent((Action<Stream, HttpContent, TransportContext>)video.WriteToStream, new MediaTypeHeaderValue("video/webm"));
            response.Content.LoadIntoBufferAsync();
            return response;
        }

Video Stream:

public async void WriteToStream(Stream outputStream, HttpContent content, TransportContext context)
        {
            try
            {
                byte[] buffer;

                var f = File.Open(_filename, FileMode.Open, FileAccess.Read);
                if (f != null)
                    buffer = new byte[f.Length];
                else
                    buffer = new byte[Int32.MaxValue];

                f.Close();

                using (var video = File.Open(_filename, FileMode.Open, FileAccess.Read))
                {
                        var length = (int)video.Length;
                        var bytesRead = 1;
                       
                        while (length > 0 && bytesRead > 0)
                        {
                            bytesRead = video.Read(buffer, 0, Math.Min(length, buffer.Length));
                            await outputStream.WriteAsync(buffer, 0, bytesRead);
                            length -= bytesRead;
                        }
                        video.Close();
                        video.Dispose();
                }
            }
            catch
            {
                throw;             
            }
            finally
            {
               outputStream.Close();
            }
        }

If the video is more than 2 meters, chrome sends a second request at the end of the video. There was a problem The remote host closed the connection. The error code is 0x80070040 Decided to increase executionTimeout.
But why is the stream retransmission not happening?