Data Collections not updating Item Attributes with Null Value

Hi -

Is this expected functionality for ASCP Standard Data Collections?  We update the Lead Times in EBS source instance with Null values and then perform Complete Refresh - Data Collections.  In the Collected Data view, we see that the Item Lead Time value collected is Null, as expected.  However, when Plan is launched, we see that the Item Lead Time value is NOT updated to null, but rather the previous value is retained.

Is this expected functionality?  Is there a workaround for this?

Thanks