User Migration doesnt migrate 1-to-many association

I'm using the UserMigration module v2.0.0 to migrate users from entities Account_OLD to Account.  Both of these entities are on the 1-side of a 1-to-many association to a Shift_Report entity (shown below)   After migrating, I should expect all Shift Report objects with a Shift_Commander_OLD association to have a matching Shift_Commander association, and yet all the new ones are empty (shown below)   The multiplicity and ownership is the same for both associations.  Is there something else I'm missing?
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