Kafka client id configuration causes authentication to fail

LogStash Version: logstash-6.3.1
Kafka Version : 1.1.0

Our company use client_id to authenticate the kafka consumer. When I config the given client_id (such as "recommend") to connect kafka client. LogStash will change the client_id to "recommend-0" so that occurred the exception "Not authorized to access topics".  How can I avoid the client_id auto changed?
 thank you for your repaly!