Primary key property has duplicate values after migration

MongoDB Atlas App Services & Realm Atlas Device Sync
1

This is my collection how it was looking on initial development of project

public final class RLMBlackBoxWarning: Object, Codable {
    @Persisted public var values: List<RLMValue>
    @Persisted public var headerKey: String
    @Persisted public var id: Int?
}

Later I coverted variable to id to primary key

public final class RLMBlackBoxWarning: Object, Codable {
    @Persisted public var values: List<RLMValue>
    @Persisted public var headerKey: String
    @Persisted(primaryKey: true) public var id: Int
}

When I try to access to access realm content I was getting error saying

Non Fatal Error: generic(Error Domain=io.realm Code=10 "Migration is required due to the following errors:

  • Property ‘RLMBlackBoxWarning.id’ has been made required.
  • Primary Key for class ‘RLMBlackBoxWarning’ has been added." UserInfo={NSLocalizedDescription=Migration is required due to the following errors:
  • Property ‘RLMBlackBoxWarning.id’ has been made required.
  • Primary Key for class ‘RLMBlackBoxWarning’ has been added., Error Code=10})
    Properties:
    {
    localizedDescription = “The operation couldn\U2019t be completed. (EpocDataKit.DrugsRealmStore.StoreError error 0.)”;
    }

To resolve this added migration block

Realm.Configuration(
            fileURL: self.makeRxQueuesSyncedDataFileAttributes().drugRealmURL,
            schemaVersion: 2,
            migrationBlock: { migration, oldSchemaVersion in
                if oldSchemaVersion < 2 {
                    migration.enumerateObjects(ofType: RLMBlackBoxWarning.className()) { oldObject, newObject in
                        // swiftlint:disable force_unwrapping
                        newObject!["id"] = oldObject!["id"]
                    }
                }
            },
            objectTypes: .drugsRLMObjectTypes
        )

After that I started getting below error

Non Fatal Error: generic(Error Domain=io.realm Code=1 “Primary key property ‘class_RLMBlackBoxWarning.id’ has duplicate values after migration.” UserInfo={NSLocalizedDescription=Primary key property ‘class_RLMBlackBoxWarning.id’ has duplicate values after migration., Error Code=1})
Properties:
{
localizedDescription = “The operation couldn\U2019t be completed. (EpocDataKit.DrugsRealmStore.StoreError error 0.)”;
}

How can I handle this scenario