syncrepl skipped entryCSN on openldap-2.4.44 on centos 6

Hi,

I see that some entryCSN have not been synced properly with the provider. I run multimaster setup and with several slaves and sometimes i see that some slaves have old entryCSNs and I am syncing them manually with -c option.

I haven't been able to track the cause nor see anything in the log to indicate the problem. However, we have had slapd become non-responsive due to IO blocking on logging. Could this cause syncrepl to miss updating the entries? Has anyone seen this behaviour?

Thanks