How to use SignalR on multiple servers?

I have a chat app that I made with dotnet core, singalR, and react native. My chat is working well when I publish it on a single server. But when I get publish it in multiple servers by docker swarm. I get this error.

Unable to connect to the server with any of the available transports. WebSockets failed: Error: There was an error with the transport.

By this error message, the app is just sometimes working normally. When I leave the page and return back it is not working again.

I am using ubuntu server. I both aligned the versions of signalR on server and client. They are both using 5.0.3. I don't have proxy server in front of the app and I m using load balancing feature of docker swarm.

Configure Service

var tokenKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["TokenKey"]));
        services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
            .AddJwtBearer(opt =>
            {
                opt.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = tokenKey,
                    ValidateAudience = false, 
                    ValidateIssuer = false,
                    ValidateLifetime = true,
                    ClockSkew = TimeSpan.Zero
                };
                opt.Events = new JwtBearerEvents
                {
                    OnMessageReceived = context =>
                    {
                        var accessToken = context.Request.Query["access_token"];
                        var path = context.HttpContext.Request.Path;

                        if (!string.IsNullOrEmpty(accessToken))
                        {
                            if (path.StartsWithSegments("/chat")
                            || path.StartsWithSegments("/dialog"))
                            {
                                context.Token = accessToken;
                            }
                        }

                        return Task.CompletedTask;
                    }
                };
            });

Configure Void

app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
            endpoints.MapHub<ChatHub>("/chat", opt => { opt.Transports = HttpTransportType.WebSockets; });     
            endpoints.MapHub<DialogHub>("/dialog", opt => { opt.Transports =  HttpTransportType.WebSockets; }); 

        });