Websocket over StompJS not able to send message to host, running Springboot

I have an Angular fontend application with a Spring Boot backend that uses websockets over Stomp. The app can successfully send websocket messages from the host to the browser. I need to now send messages from the browser but the message is failing to show up on my Spring controller containing the MessageMapping.

Here is my wesocket configuration:

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfiguration implements WebSocketMessageBrokerConfigurer {
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/connectws")
                .addInterceptors(new HttpHandshakeInterceptor())
                .setAllowedOriginPatterns("*")
                .withSockJS();
    }
    @Override 
    public void configureMessageBroker(MessageBrokerRegistry registry) { 
      registry.setApplicationDestinationPrefixes("/app"); 
      registry.enableSimpleBroker("/topic"); 
    }
}

Here is my message handler on the backend:

@Controller
public class WebsocketController {
    @MessageMapping("/sendToHost")
    public void sendToHost( Object message) {
        System.out.println("Received message: " + message );
    }

In the browser code my stompClient is able to successfully subscribe to destinations and receive messages. I use this same stompClient to attempt to publish a message to ‘/app/sendToHost’. However, the message never arrives in my “sendToHost()” Java method. I have traced through the UI publish code and it indicates that the stomClient is connected and it appears to finally send the message.

Here is my publish code.

        this.stompClient.publish({
            destination: '/app/sendToHost',
            headers: { },
            body: 'message',
        });

Any ideas or suggestions on how I can get this working. I have not included all code to just focus on what I believe to be the important code, but please let me know if additional code will help and I will gladly add it.