Having trouble changing updating swiftUI List display when sort order changes...

Hello,

I am attempting to present a list of items in SwiftUI sorted by when they were last used. Current behaviour:

1. user sees a List of items, sorted with most recently used at the top

2. user selected item X from the list (navigates to its detail view)

3. user 'uses' item X in the detail view

4. user navigates back to list view

expected behaviour: item X at the top of the list
actual behaviour: item X is still in its previous location
(see code below)

When I uncomment line 27, tapping the user button immediately (and unexpectedly) takes the user back to the list view. Is there a way I can leave the user on the detail view, but have the list be sorted when I go back to the list view?
thanks!

Code Block 
import SwiftUI
struct ContentView: View {
    @ObservedObject var list = ModelList.shared
    var body: some View {
        NavigationView {
            List(list.sorted()) {object in
                NavigationLink(destination: DetailView(object: object)) {
                    Text(object.title)
                }
            }
        }
    }
}
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}
struct DetailView: View {
    var object: ModelObject
    var body: some View {
        VStack {
            Text(object.title)
            Button("Use") {
                self.object.usedDate = Date()
/*                ModelList.shared.objectWillChange.send() */
            }
        }
    }
}
class ModelObject: ObservableObject {
    @Published var usedDate: Date = Date(timeIntervalSince1970: 0)
    let title: String
    init(title: String) {
        self.title = title
    }
}
extension ModelObject: Identifiable {
}
class ModelList: ObservableObject {
    static let shared = ModelList()
    @Published var objects: [ModelObject]
    init() {
        self.objects = [ModelObject(title: "first"), ModelObject(title: "second")]
    }
    func sorted() -> [ModelObject] {
        return objects.sorted{$0.usedDate > $1.usedDate}
    }
}