What drives the ASSIGNMENT_STARTED_ON_DATE?

Summary:

What drives the ASSIGNMENT_STARTED_ON_DATE? This is not available via HDL.

Content (required):

We have loaded learning records and have noticed that the ASSIGNMENT_STARTED_ON_DATE is populated for records loaded despite it not being part of the HDL object.

This is populating for Completed and Withdrawn assignments with a date after the completion date which is causing confusion in reporting.

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