Upgrading to VaadinWebSecurity is breaking custom WebSocket

I recently upgraded my project from Vaadin 23.1 to 23.2 and also upgraded my Spring Security configuration class to extend VaadinWebSecurity. My project also has a custom WebSocket endpoint that is exposed at a certain URL. Before the change to VaadinWebSecurity it was working fine. However after upgrading, it is not reachable any more. Instead, it seems I am getting connected to a Vaadin WebSocket. Probably the new SecurityFilterChain is overwriting my config.

Message received after connecting:

for(;;);[{"meta":{"async":true,"sessionExpired":true}}]

Security Config

@EnableWebSecurity
@Configuration
public class SecurityConfiguration extends VaadinWebSecurity {

    public static final String LOGOUT_URL = "/";
    public static final String WEBSOCKET_URl = "/websocket";

   //...

    @Override
    protected void configure(HttpSecurity http) throws Exception {

        http.authorizeRequests()
                .antMatchers(WEBSOCKET_URl)
                .permitAll();

        super.configure(http);
        setLoginView(http, LoginView.class, LOGOUT_URL);
    }

}

Sample WebSocket Handler

@Configuration
@EnableWebSocket
public class Websocket implements WebSocketConfigurer {
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry
                .addHandler(new WebSocketHandler() {
                                @Override
                                public void afterConnectionEstablished(WebSocketSession session) throws Exception {
                                    session.sendMessage(new TextMessage("this is a response"));
                                }

                                // ...

                            }, SecurityConfiguration.WEBSOCKET_URl)
                .setAllowedOriginPatterns("*");
    }
}

I created a minimal example project based on start.vaadin.com. It contains a sample WebSocket Handler.

• sample-webscoket-vaadin.zip
• Vaadin / Flow version: 23.2.1
• Java version: 17

Can someone give me some advice how to get the WebSocket running again?