On Platform Syntax XAML Issue with Global Styles

I am trying to setup a specific heightrequest for android only in my xamarin forms xaml code using onPlatform. When I specify the below Android works fine, but I dont want to specify a height for IOS as I am controlling this in my App.xaml file as a global style. For some reason when iOS is not specified here the global styles are not applied. I have read a few articles stating adding an IOS option with the value at -1, but it still doesnt show the global styles. Any ideas how I can resolve this issue?

        <Picker....>
                        <Picker.HeightRequest>
                            <OnPlatform x:TypeArguments="x:Double" >
                                <On Platform="Android" Value="30" />

                            </OnPlatform>
                        </Picker.HeightRequest>

                    </Picker>