I’m creating a test app for selecting a value in a filtersheet.
Below I put the code I use.

The problem is that the selected value in the picker isn’t shown.
This happens when I use a Binding and not when using State.
I want to use the Binding because the selected value has to be used in the calling view.

struct ContentView: View {
    @StateObject var contentListViewModel = ContentListViewModel()
    
    var body: some View {
        NavigationStack {
            VStack {
                Text(contentListViewModel.selectedNumber?.uuidString ?? "No selection")
                    .font(.system(size: 12))
                VStack() {
                    NavigationLink("Person to tap") {
                        HStack {
                            Text("Person")
                                .frame(width: 100, alignment: .leading)
                            Image(systemName: "person.circle")
                        }
                    }
                    .navigationTitle("Person")
                    
                    Spacer()
                }
            }
            .navigationTitle("Show Filter Sheet")
            .navigationBarTitleDisplayMode(.automatic)
            .toolbar {
                ToolbarItem(placement: .topBarLeading) {
                    Button(action: {
                        contentListViewModel.showFilterScreen.toggle()
                    }, label: {
                        VStack {
                            Text("Filter")
                                .font(.system(size: 12))
                            Image(systemName: "line.3.horizontal")
                                .resizable()
                        }
                    })
                    .fullScreenCover(isPresented: $contentListViewModel.showFilterScreen, onDismiss: {
                        print("Sheet has been dismissed.")
                    }) {
                        FilterSheet(selectedNumber: $contentListViewModel.selectedNumber)
                    }
                }
            }
        }
    }
}

class ContentListViewModel: ObservableObject {
    @Published var showFilterScreen: Bool = false
    
    @Published var selectedNumber: PickerOneNumber.ID?
}

The filterscreen looks like:

struct FilterSheet: View {
    @Environment(.dismiss) var dismiss
    
    @Binding var selectedNumber: PickerOneNumber.ID?
    
    @State private var selectedNumber_2: PickerOneNumber.ID?
    
    let numbers: [PickerOneNumber] = [
        .init(number: 1),
        .init(number: 2),
        .init(number: 3)
    ]
    
    init(selectedNumber: Binding<PickerOneNumber.ID?>) {
        self._selectedNumber = selectedNumber
    }
    
    var body: some View {
        VStack {
            HStack {
                Picker("Select number", selection: $selectedNumber) {
                    Text("Make selection ...").tag(nil as PickerOneNumber.ID?)
                    ForEach(numbers) { number in
                        Text(String(format: "%i", number.number)).tag(number.id as PickerOneNumber.ID?)
                    }
                }
            }
            .padding()
            .frame(maxWidth: .infinity)
            .frame(height: 200, alignment: .center)
            .background(.gray)
            
            VStack {
                Text("Selection:")
                Text(selectedNumber?.uuidString ?? "No selection")
            }
            .font(.system(size: 12))
            .padding(10)
            
            Button {
                dismiss()
            } label: {
                Text("Close")
            }
            .padding(.top, 25)
            
            Spacer()
        }
        .transition(.move(edge: .bottom))
        // .animation(.easeInOut, value: isShowing)
        
        .onAppear {
            // self.selectedNumber = numbers.first?.id
        }
    }
}

struct PickerOneNumber: Identifiable {
    let id = UUID()
    
    let number: Int
}

The problem is only the show selected value in the picker.
When I run the app the selection is ok and visible.

The error I get is the following:

Picker: the selection “Optional(17973262-4A94-4CC2-83D1-804E46871308)” is invalid and does not have an associated tag, this will give undefined results.
Picker: the selection “Optional(17973262-4A94-4CC2-83D1-804E46871308)” is invalid and does not have an associated tag, this will give undefined results.
Picker: the selection “Optional(ACCC7A38-8607-4997-89EF-BF9C78E5C167)” is invalid and does not have an associated tag, this will give undefined results.

When I change the selection in the State property it works fine with the picker but the selected value doesn’t go back to the calling view.