Seems more of an integrant question. I don't see from the example how the consumer from the first method is bind to the second one.
But if it's saying
INFO [org.apache.kafka.clients.consumer.KafkaConsumer:936] - [Consumer clientId=consumer-1, groupId=appone] Subscribed to topic(s): appone.public.crs, appone.public.users, appone.public.msfield
Then the consumer is prepared, so, it shouldn't be null?