I've managed to resolve the issue. With HA enabled, you will see this message in the logs:
2018-11-01 13:38:52,467 INFO org.apache.flink.runtime.entrypoint.ClusterEntrypoint - Actor system started at akka.tcp://flink@flink-jobmanager:40641 Without HA enabled, you will see this message in the logs: 2018-11-01 13:38:52,467 INFO org.apache.flink.runtime.entrypoint.ClusterEntrypoint - Actor system started at akka.tcp://flink@flink-jobmanager:6123 HA causes a random port assignment for the ResourceManager portion of the JobManager. This can be controlled by setting the high-availability.jobmanager.port to a fixed port and exposing it in the Kubernetes network configuration.
