Connection closed to "URL server" Websocket with stomp and sockjs

[juanito...@gmail.com]

I have a server socket implemented with spring boot and Angular 7 web page implemented like client

For using websocket on the server I have the next configuration 

@Configuration

@EnableWebSocketMessageBroker

public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Override

    public void configureMessageBroker(MessageBrokerRegistry config) {

        config.enableSimpleBroker("/alerts", "/transfers");

        config.setApplicationDestinationPrefixes("/app");

    }

    @Override

    public void registerStompEndpoints(StompEndpointRegistry registry) {

        registry.addEndpoint("/expiredControl-ws")

        .setAllowedOrigins("*").withSockJS()

        .setWebSocketEnabled(false)

        .setInterceptors(httpHandshakeInterceptor());

    }

    @Bean

    public HttpHandshakeInterceptor httpHandshakeInterceptor() {

        return new HttpHandshakeInterceptor();

    }

}

and for implementing the websocket client I have this configuration 

import {Injectable} from "@angular/core";

import * as SockJS from 'sockjs-client';

import * as Stomp from '@stomp/stompjs';

@Injectable()

export class WebSocketService {

    // Open connection with the back-end socket

    public connect() : Promise<Stomp.Client> {

        return new Promise((resolve) => {

            const stompClient = new Stomp.Client({

                webSocketFactory: () => {

                    return new SockJS('/expiredControlWs/expiredControl-ws');

                },

                debug:(args) => {

                    console.log("WebSocketService" , args);

                },

                onConnect: () => {

                   resolve(stompClient);

                },

                onDisconnect: () => {

                    console.log("WebSocketService disconnected");

                },

                reconnectDelay: 5000,

                heartbeatIncoming: 4000,

                heartbeatOutgoing: 4000

            });  

            stompClient.activate();

        });

    }

}

Dependencies that  i am using: 

---back-end

spring 5.0.12.RELEASE,

spring-boot: 2.0.6.RELEASE,

spring-websocket-5.0.12.RELEASE

---front-end

 "@stomp/stompjs": "^5.4.2",

 "sockjs-client": "^1.3.0",

Additionally I am using keyloack as security framework.

So, What is my problem?

After I done a rest request the websocket client connection dead, but this does not happen inmediatly.

After I have done a rest request when I want to send data from the client to the server, the client connection is closed. I have no idea why this happends?