https://bugs.openldap.org/show_bug.cgi?id=10591
--- Comment #6 from Howard Chu hyc@openldap.org --- To clarify a bit more, since you state this is using delta-syncrepl...
the accesslog's mdb_add can do a syncprov_op_cleanup for the accesslog's syncprov. But that has nothing to do with the syncprov_op_cleanup for the main DB's syncprov.
It wasn't clear from your report which syncprov instance you're discussing.