Are there logical differences between the automated run and your manual one?
Like manually running the sync during a time where the system idles?
Also I’ve seen slow syncs not because Zammad was slow, but because the connection to the LDAP server was temporary bad or ldap itself was slow. So that’s actually 3 factors that may degrade your performance during sync. If this permanently happens this is really odd and should not happen.
Are there logical differences between the automated run and your manual one?
Like manually running the sync during a time where the system idles?
I’m not aware of any differences. I’ve tried several times and always seen the fast manual triggered syncs and the slow scheduled. The connections to the LDAP Servers are encrypted, so I can’t see what they are talking, but it looks like zammad fetches the data in junks and take a very long time before contacting the ldap server for the next chunk. With maual syncs these pauses are shorter, as if the background job runs with lower priority.
To double check you could restart the scheduler service ( zammad-worker ) - maybe it somewhat run into trouble which slows it down. Please note that if your scheduler in general is experiencing high loads already, this may be the reason why you’re struggling with slow syncs.