SwiftUI Textfield state change stopped working with iOS 15.4.1

Question

The following code has worked fine until iOS 15.4.1. It simply enables a button next to a textfield after the value entered is greater than 100000. It still works with 15.3.1 but stopped working with 15.4.1. Any idea what was changed to prevent it from working?

    import SwiftUI
    
    struct ContentView: View {
        @State private var woid:Int? = nil
        @State var showResults = false
        private var woidFormatter:NumberFormatter = {
            let formatter = NumberFormatter()
            formatter.numberStyle = .decimal
            formatter.groupingSeparator = ""
            return formatter
        }()
        
        var body: some View {
            Form {
                Section(header: Text("Work Order Lookup")) {
                    HStack {
                        TextField("Work Order Number", value: $woid, formatter: woidFormatter)
                            .keyboardType(.numberPad)
                        Spacer()
                        
                        Button("Lookup") {
                            
                            showResults.toggle()
                        }.buttonStyle(PurpleButton(disabled: (woid ?? 0) < 100000))
                            .disabled((woid ?? 0) < 100000)
                    }
                }
            }
        }
    }
    
    struct ContentView_Previews: PreviewProvider {
        static var previews: some View {
            ContentView()
        }
    }
    
    struct PurpleButton: ButtonStyle {
        let disabled:Bool
        let cardColor:Color = Color(#colorLiteral(red: 0.5568627715, green: 0.3529411852, blue: 0.9686274529, alpha: 1))
        
        func makeBody(configuration: Configuration) -> some View {
            configuration.label
                .padding()
                .background(disabled ? Color.gray : cardColor)
                .foregroundColor(.white)
                .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
        }
    }

Answer 1

I'm not sure why it worked before but the proper signature for using optionals is this one:

    @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
    public init<F>(_ titleKey: LocalizedStringKey, value: Binding<F.FormatInput?>, format: F, prompt: Text? = nil) where F : ParseableFormatStyle, F.FormatOutput == String

Changing this line:

TextField("Work Order Number", value: $vm.woid, formatter: woidFormatter)

to this works

TextField("Work Order Number", value: $vm.woid, format: .number)