Calling SignalR client on a loop Fails using different browser - asp.net-mvc

Question

I have a problem using asynchronous task and signalR here is my scenario:
I have to page records using async task to create a csv file and updating the client using push notification via signalR here is my code:
private async Task WriteRecords([DataSourceRequest] DataSourceRequest dataRequest,int countno, VMEXPORT[] arrVmExport, bool createHeaderyn, string filePath )
{
string fileName = filePath.Replace(System.Web.HttpContext.Current.Server.MapPath("~/") + "Csv\\", "").Replace(".csv", "");
int datapage = (countno / 192322)+1;
for (int i = 1; i <= datapage; )
{
dataRequest.Page = i;
dataRequest.PageSize = 192322;
var write = _serviceAgent.FetchByRole("", "", CurrentUser.Linkcd, CurrentUser.Rolecd).ToDataSourceResult(dataRequest);
await Task.Run(()=>write.Data.Cast<AGENT>().WriteToCSV(new AGENT(), createHeaderyn, arrVmExport, filePath));
createHeaderyn = false;
i = i + 1;
double percentage = (i * 100) / datapage;
SendProgress(percentage, countno,fileName);
}
}
Here is the set up in my BaseController which calls the hub context:
public void SendNotification(string fileNametx, bool createdyn)
{
var context = GlobalHost.ConnectionManager.GetHubContext<SignalRHubHelper>();
context.Clients.User(CurrentUser.Usernm + '-' + CurrentUser.GUID)
.receiveNotification("Export", CurrentUser.Usernm, "info", fileNametx, createdyn);
}
public void SendProgress(double recordCount, int totalCount,string fileName)
{
var context = GlobalHost.ConnectionManager.GetHubContext<SignalRHubHelper>();
context.Clients.User(CurrentUser.Usernm + '-' + CurrentUser.GUID).reportProgress(recordCount, totalCount,fileName);
}
And Here is my controller Method:
public async Task<ActionResult> _Export([DataSourceRequest] DataSourceRequest dataRequest, string columns,int countno, string menunm)
{
var fileNametx = AgentsPrompttx + DateTime.Now.ToString(GeneralConst.L_STRING_DATE4) + ".csv";
SendNotification(fileNametx, false);
var filePath = System.Web.HttpContext.Current.Server.MapPath("~/") + "Csv\\";
var vmexport = new JavaScriptSerializer().Deserialize<VMEXPORT[]>(columns);
dataRequest.GroupingToSorting();
dataRequest.PageSize = 0; // set to zero
await WriteRecords(dataRequest,countno, vmexport, true, filePath + fileNametx);
SendNotification(fileNametx, true);
return File(filePath + fileNametx, WebConst.L_CONTENTTYPE_APP_OCTET, fileNametx);
}
the main problem is when i request 4 times download.. means 4 tasks running asynchronously. It creates notification when i use same browser. but when i use IE and Google it fails to give me the progress. It creates the file no problem with file creation but on updates only it doesnt work fine. can someone correct me in this way
Update
The problem is when I use multiple Browser which invokes OnDisconnected() when navigating to other pages. Which stops the connection to other connected Hub context.