Hi, I started a new project selecting SwiftData as db by default. I created my models as default. @Model class Trip { var id: UUID public private(set) var Name: String public private(set) var Members: [Member] public private(set) var Buys: [Buy] public func removeBuy(indexBuyToRemove: Int) { self.Buys.remove(at: indexBuyToRemove) } } @Model class Member: Identifiable, Equatable { var id: UUID public private(set) var Name: String } @Model class Buy: Identifiable, Equatable { var id: UUID public private(set) var Author: Member public private(set) var Ammount: Double public private(set) var Title: String } I initialize my trips as this in my ContentView @Query public var tripsList: [Trip] And then pass this list in every other view. I also have a ModelContext as default, passed like this in the @Main @main struct MainApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([ Member.self, Buy.self, Trip.self ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() .preferredColorScheme(.dark) } .modelContainer(sharedModelContainer) } } And defining in the other views like this @Environment(\.modelContext) var modelContext Now. For the problem of consistency. Whenever I add a new Trip I do this or delete (as .onDelete in the List) public func addTrip(Trip: Trip) { modelContext.insert(Trip) } private func deleteItems(offsets: IndexSet) { withAnimation { for index in offsets { modelContext.delete(tripsList[index]) } } } And everything works fine. The problem starts when I try to delete a Buy element of the Trip.Buys: [Buy]. I do like this: private func deleteItems(offsets: IndexSet) { withAnimation { for index in offsets { let buyToRemove = trip.Buys[index] trip.removeBuy(indexBuyToRemove: index) do { try modelContext.save() } catch {} } } } The delete is not consistent. What am I missing? What am I doing wrong? Thank you for your help