Java Websocket Controller never called

Question

I use Java Spring Boot 3.2.0 and spring-boot-starter-websocket The Handshake to connect to the Websocket is successfull, but i cant get my Controller invoked.

Config:

@Configuration
@EnableWebSocketMessageBroker
public class WebsocketConfiguration implements WebSocketMessageBrokerConfigurer
{

  @Override
  public void registerStompEndpoints(StompEndpointRegistry registry) {
    registry.addEndpoint("/gs-guide-websocket").setAllowedOrigins("*");
  }

  @Override
  public void configureMessageBroker(MessageBrokerRegistry config) {
    config.enableSimpleBroker("/topic");
    config.setApplicationDestinationPrefixes("/app");
  }
}

Controller:

@Controller
@CrossOrigin(origins = "*")
public class ConnectionController {


  @MessageMapping("/audio")
  @SendTo("/topic/audio")
  public String sendAudio(String message)
  {
    return "connected: " + message;
  }

}

I use a Websocket client to subscribe to the topic like that:

SUBSCRIBE
destination:/topic/audio

and send a message to the Controller like that:

SEND
destination:/app/audio

Test

Why does my controller not get called?

Im using Websocket King as the Client