Alpakka-kafka - Consumer sends LeaveGroup request

So my problem is when i starting my kafka consumer stream, after consuming some records AbstractCoordinator sends LeaveGroup request to coordinator and then Consumer is stopping, why it happens?

[INFO ] [26/12/2019 13:25:45] [] o.a.k.c.c.i.AbstractCoordinator | [Consumer clientId=consumer-1, groupId=product-projector] Sending LeaveGroup request to coordinator (id: 2147483645 rack: null)
[INFO ] [26/12/2019 13:25:45] [akka://productProjector/system/kafka-consumer-1] a.a.RepointableActorRef | Message [akka.kafka.KafkaConsumerActor$Stop$] from Actor[akka://productProjector/system/StreamSupervisor-0/$$a#246015084] to Actor[akka://productProjector/system/kafka-consumer-1#1371580266] was not delivered. [1] dead letters encountered. If this is not an expected behavior, then [Actor[akka://productProjector/system/kafka-consumer-1#1371580266]] may have terminated unexpectedly, This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

My consumer config:

    consumer {
      # Tuning property of scheduled polls.
      # Controls the interval from one scheduled poll to the next.
      poll-interval = 50ms

      # Tuning property of the `KafkaConsumer.poll` parameter.
      # Note that non-zero value means that the thread that
      # is executing the stage will be blocked. See also the `wakup-timeout` setting below.
      poll-timeout = 50ms

      # The stage will delay stopping the internal actor to allow processing of
      # messages already in the stream (required for successful committing).
      # Prefer use of `DrainingControl` over a large stop-timeout.
      stop-timeout = 30s

      # Duration to wait for `KafkaConsumer.close` to finish.
      close-timeout = 20s

      # If offset commit requests are not completed within this timeout
      # the returned Future is completed `CommitTimeoutException`.
      # The `Transactional.source` waits this ammount of time for the producer to mark messages as not
      # being in flight anymore as well as waiting for messages to drain, when rebalance is triggered.
      commit-timeout = 15s

      # If commits take longer than this time a warning is logged
      commit-time-warning = 1s

      # Not used anymore (since 1.0-RC1)
      # wakeup-timeout = 3s

      # Not used anymore (since 1.0-RC1)
      # max-wakeups = 10

      # If set to a finite duration, the consumer will re-send the last committed offsets periodically
      # for all assigned partitions. See
      commit-refresh-interval = infinite

      # Not used anymore (since 1.0-RC1)
      # wakeup-debug = true

      # Fully qualified config path which holds the dispatcher configuration
      # to be used by the KafkaConsumerActor. Some blocking may occur.
      use-dispatcher = "akka.kafka.default-dispatcher"

      # Properties defined by org.apache.kafka.clients.consumer.ConsumerConfig
      # can be defined in this configuration section.
      kafka-clients {
        bootstrap.servers = ${KAFKA}
        # Disable auto-commit by default = false

      # Time to wait for pending requests when a partition is closed
      wait-close-partition = 500ms

      # Limits the query to Kafka for a topic's position
      position-timeout = 5s

      # When using `AssignmentOffsetsForTimes` subscriptions: timeout for the
      # call to Kafka's API
      offset-for-times-timeout = 5s

      # Timeout for akka.kafka.Metadata requests
      # This value is used instead of Kafka's default from ``
      # which is 1 minute.
      metadata-request-timeout = 5s

      # Interval for checking that transaction was completed before closing the consumer.
      # Used in the transactional flow for exactly-once-semantics processing.
      eos-draining-check-interval = 30ms