Hello guys!

I am scratching my head with the following:)

I have a 3 column NavigationSplitView where a detailView takes a flight which is a Core Data model like so (minimal reproducible code):

import SwiftUI

enum SideBarMenuCategory: Int, CaseIterable, Identifiable {
    case flights
    var id: Int { rawValue }
}

class FlightModel: ObservableObject {
    let id: UUID
    let text: String

    init(text: String) {
        self.id = UUID()
        self.text = text
    }
}

class RouteManager: ObservableObject {
    @Published var selectedCategory: SideBarMenuCategory? = .flights
    @Published var visibility: NavigationSplitViewVisibility = .automatic
    @Published var selectedFlight: FlightModel? = nil

    @Published var selectedFlights = Set<UUID>() {
        didSet {
            updateSelectedFlight()
        }
    }

    let flightStore = FlightStore.instance

    func updateSelectedFlight() {
        guard selectedFlights.count == 1,
              let flightID = selectedFlights.first
        else {
            selectedFlight = nil
            return
        }
        selectedFlight = flightStore.findFlight(by: flightID)
    }
}

class FlightStore: ObservableObject {
    static let instance = FlightStore()

    private init() {}

    @Published var flights: [FlightModel] = [FlightModel(text: "Test"), FlightModel(text: "Test 2")]

    func findFlight(by id: UUID?) -> FlightModel? {
        flights.first { $0.id == id }
    }
}

struct SidebarView: View {
    @Binding var selectedCategory: SideBarMenuCategory?

    var body: some View {
        List(selection: $selectedCategory) {
            NavigationLink(value: SideBarMenuCategory.flights) {
                Label("Flights", systemImage: "book")
            }
        }
    }
}

struct FlightsOverView: View {
    @EnvironmentObject var routeManager: RouteManager
    @EnvironmentObject var flightStore: FlightStore

    var body: some View {
        List(flightStore.flights, id: \.id, selection: $routeManager.selectedFlights) { flight in
            HStack {
                Text(flight.id.uuidString)
                Spacer()
                Text(flight.text)
            }
            .tag(flight.id)
        }
    }
}

struct SplitView: View {
    @StateObject var routeManager = RouteManager()
    @StateObject var flightStore = FlightStore.instance

    var body: some View {
        NavigationSplitView(columnVisibility: $routeManager.visibility) {
            SidebarView(selectedCategory: $routeManager.selectedCategory)
                .navigationTitle("Menu")
        } content: {
            SecondColumnView()
        } detail: {
            ThirdColumnView()
        }
        .environmentObject(routeManager)
        .environmentObject(flightStore)
    }
}

struct SecondColumnView: View {
    @EnvironmentObject var routeManager: RouteManager

    var body: some View {
        if let selectedCategory = routeManager.selectedCategory {
            switch selectedCategory {
            case .flights:
                FlightsOverView()
            }
        } else {
            EmptyView()
        }
    }
}

struct ThirdColumnView: View {
    @EnvironmentObject var routeManager: RouteManager

    var body: some View {
        if let category = routeManager.selectedCategory {
            switch category {
            case .flights:
                if let flight = routeManager.selectedFlight {
                    FlightDetailView(flight: flight)
                }
            }
        } else {
            Text("Select View")
        }
    }
}

class DetailVM: ObservableObject {
    init() {
        print("DetailVM is Init")
    }

    deinit {
        print("DetailVM is Deinit")
    }
}

struct FlightDetailView: View {
    @ObservedObject var flight: FlightModel
    @StateObject var detailVM = DetailVM()

    @State var isOn = false

    var body: some View {
        VStack(alignment: .center) {
            Text(flight.text)
            Toggle("", isOn: $isOn)
        }
        .task {
            print("I want to set something up")
        }
        .onDisappear {
            print("I want to perform some checks")
        }
    }
}

FlightsOverView holds List with selection. That selection returns a Set<UUID> which I filter and return a selectedFlight. The change takes place as expected and view updates. However, all @StateObject and @State held by FlightDetailView do not reset when changing selection (.task runs exactly once on the initial selection and .onDisappear is never invoked). I am migrating from NavigationStack where this isn't an issue as the view disappears before another one can be selected. How could this be fixed in NavigationSplitView? I tried assigning a .id(flight.id) to the view but this only causes in @StateObjects of that view to init each time flight selection is changed but no deinit takes place.