HSDL - Update/Correct Position Code, Job and Department for Assignments

Hello experts,

I need your guidance for the following case:

Summary:

Recently there were moved around 200 employees from one LE to another LE (with Effective Star Date: 28-03-2024).
After this transfer all the assignments needed to be updated with the new positions, jobs and departments:

We tried to achieve this change using the following HSDL template (provided here):

Errors that I receive:

IMPORT ERRORS

The line for component WorkRelationship with instruction MERGE doesn't include values that define a unique reference to the record.
You must provide a valid reference to the parent record. Ensure that the parent record is supplied in the same file, or has already been created.