Form - Multiplatform - Alignment off - HStack ?

Not sure what could cause this. the UI align differently running on iPhone versus running on Mac. If I remove the HStack, it works but I still would like to know why, and if there is a way to make it right on both platforms.

Thank you

here is my code

    @State private var viewModel = FirmwareSelectionViewModel()
    
    var body: some View {
        Form {
            Section("Setup Name") {
                TextField ( "", text: $viewModel.setupName  )
                    .foregroundColor(.green )
                .disableAutocorrection(true)
                    .onSubmit {
                          print ("On Submit")
                      }
            }
            
            Section("Battery") {
                HStack() {
                    Text("Volt")
                    TextField("", value: $viewModel.Vnominal, format: .number)
                        .textFieldStyle(.roundedBorder)
                        .foregroundColor(.green )
                        #if !os(macOS)
                        .keyboardType(.decimalPad)
                        #endif
                        .onChange(of: viewModel.Vnominal) {
                            viewModel.checkEntryValidity()
                            print("Updated Vnominal: \(viewModel.Vnominal)")
                        }
                    
                    Text("Ah")
                    TextField("", value: $viewModel.batteryCapacity, format: .number)
                        .textFieldStyle(.roundedBorder)
                        .foregroundColor(.green )
                        #if !os(macOS)
                        .keyboardType(.decimalPad)
                        #endif
                        .onChange(of: viewModel.batteryCapacity) {
                            viewModel.checkEntryValidity()
                            print("Updated Battery Capacity: \(viewModel.batteryCapacity)")
                        }
                }
                
            }
            
            
            Section("Firmware Type") {
                Picker(selection: $viewModel.selectedType, label: EmptyView()) {
                    ForEach(TypeOfFirmware.allCases) { type in
                        Text(type.rawValue).tag(type as TypeOfFirmware)
                            .foregroundColor(.green )
                    }
                }
                .pickerStyle(SegmentedPickerStyle())
                
                
                Picker(selection: $viewModel.selectedFirmware, label: EmptyView()) {
                    ForEach(viewModel.availableFirmware) { firmware in
                        Text(firmware.rawValue.capitalized).tag(firmware as Firmware)
                    }
                }
                .pickerStyle(SegmentedPickerStyle())
            }
        }
        .onChange(of: viewModel.selectedType) {
            viewModel.resetFirmwareSelection()
        }
        .navigationTitle("Firmware Selection")
        
    }
}