Hi @cabrinoob,
From what I quickly see the chart you are using have a default configuration for elasticsearch here. When an Elasticsearch is configured Logstash is enabling Logstash X-Pack monitoring. To disable it you can remove elasticsearch configuration from your values if you don't need it or enforce xpack.monitoring.enabled=false.
Please note also that helm/charts/stable/logstash is not maintained by Elastic, we are just releasing elastic/helm-charts/logstash which will be available on Elastic Helm repo and Helm Hub pretty soon.