Hello, Not sure if you still have the same issue. I had the same problem, but today after several trials I found out that it seems to be solved by simply naming the configurations, i.e.: let modelConfigForNoCloudSync = ModelConfiguration("local", schema: modelNotForCloudSyncing, cloudKitDatabase: .none) let modelConfigForCloudSync = ModelConfiguration("synced", schema: modelsForCloudSyncing, cloudKitDatabase: .automatic) This seems to be enough to get rid of all the 'duplicate stores' issues, and the data syncs as intended.