We have a custom property defined in the schema of managed object. Every time this custom property changes, OpenIDM sees that the record is updated and syncs it to the target which is AD in our case. Is there a way to make OpenIDM to not sync when this property changes?
You can change that property directly via repository service (/repo/managed/user) so that the managed object service is not picking up on the event. Such call would need to be wrapped in a custom endpoint.