Filebeat wont send all messages to kafka

[marcusedvardsson]

Filebeat 7.2.0
Kafka 2.2.0 (apache, not confluent)
Logstash 7.2.0
ElasticSearch 7.2.0
Kibana 7.2.0

The setup is: Filebeat -> kafka -> logstash -> elasticsearch

Filebeat (or is Logstash the problem?) will not sent ALL messages to kafka. It's connecting successfully and some messages will end up in elasticsearch but not all of them. I can't see where the problem is.

When I change output directly to elasticsearch everything will be sent to elasticsearch.

No errormessages in filebeat nor kafka.

Part of filebeat.yml

#-------------------------- Kafka output ------------------------------
output.kafka:
  enabled: true
  hosts: ["hostname:port"]
  topic: 'filebeat'
  partition.round_robin:
    reachable_only: false

  required_acks: 1
  compression: gzip
  max_message_bytes: 1000000

#============================== Xpack Monitoring ===============================
xpack.monitoring.enabled: true
xpack.monitoring.elasticsearch:
hosts: ["es_host:es_port"]

#==========================#
LOGSTASH PIPELINE:

input {
  kafka {
    bootstrap_servers => "server:port"
    topics => ["metricbeat", "filebeat", "heartbeat"]
    id => "logstash_kafka_beats"
  }
}

filter {
  json {
    source => "message"
  }
}

output {
  elasticsearch {
    hosts => ["http://ipaddress:9200"]
    index => "%{[@metadata][beat]}-%{[@metadata][version]}-%{+YYYY.MM.dd}"
  }
}