ObservableObject with Binding cause sheet crash SwiftUI

I have View with button that display sheet and after first sheet dismiss, I need to display a second sheet, when I use ObservableObject in Binding the View crash after showing the second sheet:

Root:

class Benef: ObservableObject {
    @Published var val: String = ""
}

@main
struct TestApp: App {
    @StateObject var benef = Benef()
    var body: some Scene {
        WindowGroup {
            ContentView(testt: $benef.val)
            
        }
    }
}

ContentView:

enum Test: Identifiable {
    case one
    case two
    
    var id: String {
        switch self {
        case .one : return "One"
        case .two : return "Two"
        }
    }
}

struct ContentView: View {
    @Environment(\.dismiss) private var dismiss
    @State private var showingFirst: Test?
    @State private var showingSecond: Test?
    @Binding var testt: String

    var body: some View {
        VStack {
            Button("Show First Sheet") {
                showingFirst = .one
            }
        }
        .sheet(item: $showingFirst) { tt in
            FirstSheetiew {
                showingSecond = .two
            }
        }
        .sheet(item: $showingSecond) { tt in
            VStack {
                Text("Second Sheet")
                Button("Dismiss") {
                    dismiss()
                }
            }
        }
    }
}

struct FirstSheetiew: View {
    @Environment(\.dismiss) private var dismiss

    let action: () -> Void
    
    var body: some View {
        VStack {
            Text("First Sheet")
            Button("Dismiss") {
                action()
                dismiss()
            }
        }
    }
    
}

Crash error:

"Application tried to present modally a view controller <TtGC7SwiftUI29PresentationHostingControllerVS_7AnyView: 0x12a01b600> that is already being presented by <TtGC7SwiftUI19UIHostingControllerGVS_15ModifiedContentVS_7AnyViewVS_12RootModifier: 0x12a814e00>."_

PS: if I change @StateObject var benef = Benef() by @State var benef = "", it work