TCP Plugin - Error: event executor terminated

Hello, I'm facing an issue with the TCP input plugin in Logstash:

[2020-08-31T11:57:15,669][ERROR][logstash.javapipeline    ][main][ebfb52d241eb37911098921f56a3a2be4b082eb7a6e749166438a3e26fe28ccb] A plugin had an unrecoverable error. Will restart this plugin.
  Pipeline_id:main
  Plugin: <LogStash::Inputs::Tcp codec=><LogStash::Codecs::CSV id=>"csv_caf8e7ca-9228-42b8-9f4f-480b325e6962", enable_metric=>true, separator=>",", quote_char=>"\"", include_headers=>false, autogenerate_column_names=>true, skip_empty_columns=>false, autodetect_column_names=>false, charset=>"UTF-8">, id=>"ebfb52d241eb37911098921f56a3a2be4b082eb7a6e749166438a3e26fe28ccb", type=>"tcp", port=>443, enable_metric=>true, host=>"0.0.0.0", mode=>"server", proxy_protocol=>false, ssl_enable=>false, ssl_verify=>true, ssl_key_passphrase=><password>, tcp_keep_alive=>false, dns_reverse_lookup_enabled=>true>
  Error: event executor terminated
  Exception: Java::JavaUtilConcurrent::RejectedExecutionException

This is how my config looks like:

input {
  beats {
         port => 5044
  }
  tcp {
    port => 443
    codec => csv
    type => "tcp"
  }
}

#filter {
#}

output {
  if [@metadata][pipeline] {
    elasticsearch {
      hosts => "localhost:9200"
      manage_template => false
      index => "logstash-%{[fields][flavor]}-%{+YYYY.MM.dd}"
      pipeline => "%{[@metadata][pipeline]}"
    }
  } else if [type] == "tcp" {
    elasticsearch {
      hosts => ["localhost:9200"]
      index => "logstashtcp-%{+YYYY.MM.dd}"
    }
  } else {
    elasticsearch {
      hosts => ["localhost:9200"]
      index => "logstash-%{[fields][flavor]}-%{+YYYY.MM.dd}"
  }
}

Does anyone has an idea what the problem might be? Many thanks in advance.