Cluster takes around 48 hours to synchronize after deletion

Dear all,

We have an OpenLDAP 2.4 cluster of three nodes configured in multi-master and accessed through a VIP in round-robin. The three machines run RHEL7.

We noticed that deletion of an entry (done from a Windows machine onto the first node via Oracle's tool ldapmodify.exe) takes a long time (about 48 hours) to be replicated in the cluster.

Here's the relevant extract of cn=config for the first node:

olcSyncrepl: {0}rid=001 provider=ldap://mynode2:389/ bindmethod=simple
 binddn="cn=Replicator,dc=mydomain,dc=org" credentials=1234567890 searchbase="dc=mydomain,dc=org" scope=sub schemachecking=on type=refreshAndPersist
 retry="30 5 300 +" keepalive="60:5:10"
olcSyncrepl: {1}rid=002 provider=ldap://mynode3:389/ bindmethod=simple
 binddn="cn=Replicator,dc=mydomain,dc=org" credentials=1234567890 searchbase="dc=mydomain,dc=org" scope=sub schemachecking=on type=refreshAndPersist
 retry="30 5 300 +" keepalive="60:5:10"
olcMirrorMode: TRUE

We looked up for the offending entry (thisentry) in all nodes' logs and we found this line on mynode3:

Jun 18 14:18:20 mynode3 slapd[8871]: conn=1987936 op=14 DEL dn="dc=thisentry,ou=myou,ou=foobars,dc=mydomain,dc=org"

There are no other references to thisentry (apart from SRCH operations) on node1 and node2, even if the entry was originally deleted from node1, as said above.