sync replication fails

[RUMI Szabolcs <rumi_ml@rtfm.hu>]

Hello!

I've got a syncrepl setup with the following settings:

provider slapd.conf:

overlay syncprov
syncprov-checkpoint 100 10
syncprov-sessionlog 100

consumer slapd.conf:

syncrepl rid=100
        provider="ldaps://ldap-master.com.com"
        binddn="cn=syncrepl,ou=services,dc=com,dc=com"
        bindmethod=simple
        credentials="secret"
        searchbase="dc=com,dc=com"
        scope=sub
        type=refreshOnly
        interval=00:00:10:00

provider log:

Dec  4 21:15:23 ldap-master slapd[18046]: conn=15053 fd=37 ACCEPT from IP=<slave_ip>:56390 (IP=0.0.0.0:636)
Dec  4 21:15:24 ldap-master slapd[18046]: conn=15053 fd=37 TLS established tls_ssf=256 ssf=256
Dec  4 21:15:24 ldap-master slapd[18046]: conn=15053 fd=37 closed (connection lost)

consumer log:

Dec  4 21:15:24 ldap-slave slapd[6149]: do_syncrep1: rid 100 ldap_sasl_bind_s failed (-1)
Dec  4 21:15:24 ldap-slave slapd[6149]: do_syncrepl: rid 100 quitting

I've double checked the credentials, they're OK.
/etc/openldap/ldap.conf has "TLS_REQCERT never" in order to exclude certificate issues.

What could be wrong?
Maybe it tries to authenticate by SASL despite bindmethod=simple?

Thanks,
Sab