Filebeat connect with Kafka Kerberos(SASL_SSL) not working

Continuing the discussion from [Filebeat connect with Kafka Kerberos(SASL_SSL) not working](https://discuss.elastic.co/t/filebeat-connect-with-kafka-kerberos-sasl-ssl-not-working/246160/10):

@ascherbakov686, can you please share more about the solution? what's wrong on the server side? we have the same issue, and want to know the fix.

hi, i don't know solution for kerberos, now work by certificate authentication.

Thanks @ascherbakov686 for your information. yes, it is nothing with kerberos, but it failed with certificate authentication. but if we connect to a Kafka without kerberos but the same certificate, it works.
It could be something wrong at Kafka server side, but I don't know where it is.