nsPredicate disappeared when updated

I am working on a SwiftUI project and in a subview I use @FetchRequest to fetch data from CoreData. I have a menu to let user select which data to fetch, and by default I want to fetch all datas.

The problem is when user open the menu and select a category then it refetch the data, it's correct and when user close the menu, the nsPredicate that the user have given will disappear and switch to the default predicate.

I tried to write the same pattern code on 'EarthQuake' sample app, it has the same problem.

And here is the code:

            List(selection: $selection) {
                ListView(search: $searchText)
            }
            .background(toggle ? Color.red.opacity(0.01) : nil)
            .toolbar {
                ToolbarItem(placement: .bottomBar) {
                    Button {
                        toggle.toggle()
                    } label: {
                        Text("Toggle")
                    }
                }
            }
            .searchable(text: $searchText)

ListView:

struct ListView: View {
    @FetchRequest(sortDescriptors: [SortDescriptor(\.time, order: .reverse)]) // predicate: nil
    private var quakes: FetchedResults<Quake>
    @Binding var search: String

    var body: some View {
        ForEach(quakes, id: \.code) { quake in
            NavigationLink(destination: QuakeDetail(quake: quake)) {
                QuakeRow(quake: quake)
            }
        }
        .onChange(of: search) { newValue in
            quakes.nsPredicate = newValue.isEmpty ? nil : NSPredicate(format: "place CONTAINS %@", newValue)
        }
    }
}

I can filter data by typing in the search field but when I click on Toggle Button, it may refresh the ParentView which cause the @fetchRequest to update and nsPredicate return to nil.

Is this a bug? Or maybe my understand was wrong. And is there any good suggestions?