Header issue in logstash csv output

hi all, i am using following logstash configuration:

input {
elasticsearch {
hosts => ["localhost:9200"]
index => "disp_2019-04-08"
}
}

filter {
mutate {
  add_field => {
   "P_date" => "%{PDate}"
   
  }
  }
mutate { gsub => [ "PDate", "-", "/" ] }

mutate {
	add_field => {
		"Disp_log" => "%{PDate}|%{Date}|%{Time}|%{PacketSerial}"
	}
	}
}
output {
csv {
fields => ["Disp_log"]
path => "E:/logstashlog/disp_logs/disp_%{P_date}.csv"
csv_options => {
        "write_headers" => true
        "headers" =>["PDate|Date|Time|PacketSerial"]
}
}
  stdout { codec => rubydebug }

}

but the problem is that, when i started the logstash, in the created csv output, there is a header for every record while it is needed to have just one record for csv output file. how can i handle this issue? could you please advise me? many thanks.

I believe that is working as expected. There is an issue open to change that.

is there any way to have just one header for all records?