Help setting parent/child link through API

We're trying to create some child work items automatically when a particular work item type is created. The code below to create the link executes without error, but the link is not present in RTC. The code was adapted from 'Programmatic Link Creation'; note that this is being executed from a service.

In this example saveItem is the parent and newItem is the child.

...
// save new work item
workItemServer.saveWorkItem2(newItem, workItemServer.resolveWorkItemReferences(newItem, null), null);

// get references for new item
IWorkItemReferences itemReferences = workItemServer.resolveWorkItemReferences(newItem, null);
// create reference for the save item
IReference parentReference = WorkItemLinkTypes.createWorkItemReference(saveItem);
// create link type of parent for save item
ILinkType parentLink = ILinkTypeRegistry.INSTANCE.getLinkType(WorkItemLinkTypes.PARENT_WORK_ITEM);
// create link for save item to new item
itemReferences.getReferences(parentLink.getTargetEndPointDescriptor()).add(parentReference);
...

Also tried adding this to the end

// save changes
workItemServer.saveWorkItem2(newItem, workItemServer.resolveWorkItemReferences(newItem, null), null);

Any ideas or missing details?

Thanks