Click the # under the far right Id column of the subscription that didn't switch to upgrade state. Then configure the following for it.
Status: Upgraded to other
Previous Status: Active
Next click the # under the far right Id column for the new subscription. Then configure the following for it.
Replaces subscription: Id of the previous subscription
This should put it in an upgrade state properly. My guess is it didn't behave properly due to the manual subscription given to them by the import.