The migration script should set the Version of the migrated topic references to that of the source AttributeValue. This was inadvertently overlooked during development since, originally, topic references couldn’t be versioned. As a result, rolling back to a version from before the 5.0.0 version results in topic references getting deleted.

Should ideally apply a retroactive patch for migrated topics by joining them against Attributes with a match between AttributeValue and target_TopicID.

Similarly, the default version for existing relationships should be set to the first version of the topic, since relationships can now be versioned as well. This likely defaulted to the date of the migration.