SignalR IOS client, web socket transport cannot call the method from server

I am using SignalR-ObjC Client to provide communication between IOS application and .Net server.

I can connect using longpulling and call methods from a self-hosted cross-origin server without any errors. But due to my application needs, I have to use WebSocket. I have a Singleton Manager like:

@implementation SignalRManager
static int reconnectingTry;
+ (id)sharedManager {
    static SignalRManager *sharedHttpManager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedHttpManager = [[self alloc] init];
        sharedHttpManager.hubConnection = [SRHubConnection connectionWithURL:@"http://xxx:8080/signalr"];
        sharedHttpManager.proxy = [sharedHttpManager.hubConnection createHubProxy:@"myhub"];
    });

    return sharedHttpManager;
}
+(SRHubProxy *)proxy
{
    return [[SignalRManager sharedManager] proxy];
}

+(SRHubConnection *)connection
{
    return [[SignalRManager sharedManager] hubConnection];
}

+(void)start
{
    SRWebSocketTransport *transport = [[SRWebSocketTransport alloc] init];

    [[SignalRManager connection] start:transport];

}
+(void)stop
{
    [[SignalRManager connection] stop];
}

and im calling like:

 [[SignalRManager proxy] invoke:@"Hello" withArgs:[NSArray array]];

I make the connection and the server can call the client method, but when I try to call the method from the client to the server, I get a "Request failed: Bad Request (400)" error.