Calling any function on ondisconnectedasync task in signalr hub

See more:

Javascript

.NET

Ajax

MVC

SignalR

Hi!
I have problem with client side implementation of signalrHub.
This is my ChatHub hub

public class ChatHub : Hub
    {

        public string GetConnectionId()
        {
            return Context.ConnectionId;
        }

        public override Task OnConnectedAsync()
        {


            // Groups.AddToGroupAsync(Context.ConnectionId, name);
           
            return base.OnConnectedAsync();
        }

        public override async Task OnDisconnectedAsync(Exception exception)
        {
            
           await  Clients.Client(GetConnectionId()).SendAsync("diss", Context.ConnectionId);
          await base.OnDisconnectedAsync(exception);
        }
}

and here is my js code

<pre> var connection = new signalR.HubConnectionBuilder()
    .withUrl("/chatt", {
        accessTokenFactory: () => "testing"
    })
    .build();


    connection.start().then(function () {
    connection.invoke('GetConnectionId')
    .then(function (connectionId) {
       //alert(connectionId);
       removeConnectionID(connectionId);
    })

    }).catch(err => console.error(err));

     connection.on("diss", function(connectionId) {
   
         removeConnectionID(connectionId);
        //console.log(connectionId);
    });

    async function removeConnectionID(id) {
        await  $.get("/Chat/Test") ;
        }

when i call removeConnectionID from connection.start()...
ajax call executes and takes me to Test action
but when i call removeConnectionID from connection.on("diss", ...
(OnDisconnectedAsync)
nothing happens and i dont get any errors

What I have tried:

tried sending console.log to all clients from connection.on("diss", ...
(OnDisconnectedAsync) and it worked fine
and tried to call same function from connection.start() and function works.
i think problem is that hub closes connection before action is done but dont know how to fix it!

Any help is appreciated!!!