Spring Boot Kafka listener is inconsistent

I am trying to have several different Spring Cloud Microservices all connect to a Kafka/Zookeeper Cluster, all within Kubernetes. The Microservices are using org.springframework.kafka:spring-kafka - as both consumers and producers of events.

All of the services connect to kafka okay - and topics are created; however the consumers of each service are very inconsistent.

For example, when the services start one time, all of the consumers will listen for the message and the function is invoked. But then, when I restart everything (kafka and zookeeper included), it will either just not work, or some of the consumers in different services will work etc...

Here is some of my config - I don't have any Java-based config - just in my application.yml as follows:

spring:

  ....

  kafka:
    consumer:
      bootstrap-servers: api-kafka.default.svc.cluster.local:9092
      auto-offset-reset: earliest
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      group-id: api-event
      enable-auto-commit: false

    producer:
      bootstrap-servers: api-kafka.default.svc.cluster.local:9092
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
      ack-mode: manual

...

And my main class:

@EnableCaching
@SpringBootApplication
@EnableJpaRepositories
@EnableDiscoveryClient
@EnableKafka /* <<<<<<<------------- ENABLED HERE */
public class ExampleServiceApplication {

  public static void main(String[] args) {
    SpringApplication.run(ExampleServiceApplication.class, args);
  }

  .....
}

And finally, my consumer:

@Component
public class MessageListener {

  @KafkaListener(
      topics = "myTopic")
  public void eventListener(String serializedMessage) {
    try {
....

The messages are getting sent to the broker fine, but just aren't consumed by the other services.

I realize that there is no mapping to the topics on each of the service properties, how do I do this via application.yml?

I bet I'm making a really nooby mistake but yeah! I'd really appreciate any comments or help