Strange padding above the CustomKeyboard about customkeyboardkit HOT 4 CLOSED

struct ContentView: View {
    @State private var text = "ExampleText"
    
    var body: some View {
        ScrollView {
            VStack {
                Spacer()
                TextField("Hello", text: $text)
                    .useDecimalPickerStyle()
                Spacer()
            }
            .frame(height: 800)
        }
        .background(Color.green)
    }
}

extension TextField {
    func useDecimalPickerStyle() -> some View {
        self.customKeyboard(.decimalPicker)
    }
}
extension CustomKeyboard {
    static var decimalPicker: CustomKeyboard {
        CustomKeyboardBuilder { textDocumentProxy, submit, playSystemFeedback in
            DecimalPicker(handler: textDocumentProxy)
        }
    }
}

struct DecimalPicker: View {
    let isWheel = true
    let handler: UITextDocumentProxy
    
    var body: some View {
        VStack(alignment:.leading) {
            HStack {
                Button(action: {
                }) {
                    Text(self.isWheel ? "キーボード入力に切り替える" : "ピッカー入力に切り替える")
                        .foregroundColor(Color.blue).font(Font.system(size: 18))
                }
                .padding()
                Spacer()
                Button(action: {
                }) {
                    Text("完了").foregroundColor(Color.blue).font(Font.system(size: 18))
                }
                .padding()
            }
            .background(Color(red: 245/255, green: 245/255, blue: 245/255))
            Spacer()
        }
        .frame(height: 300)
        .background(Color.red)
    }
}

struct ContentView: View {
    @State private var text = "ExampleText"
    
    var body: some View {
        ScrollView {
            VStack {
                Spacer()
                TextField("Hello", text: $text)
                    .useDecimalPickerStyle()
                Spacer()
            }
            .frame(height: 800)
        }
        .background(Color.green)
        .padding(.bottom, 10)      //this padding potentially causing issues?
        .background(Color.blue) //padding is now highlighted in blue
    }
}