Xamarin Forms Secondary ToolbarItem on TabbedPage on iOS

Question

My app behaves very weird in iOS, I have a TabPage with 3 tabs. In the first image, you can see that I have 4 Secondary ToolbarItems in the first tab. It is strange that on the Map page, where I do not have an additional tool element, the space between the NavigationBar Map still exists. Does anyone know how to fix this, or if it is a Xamarin error?

NavPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
            xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
            xmlns:view="clr-namespace:CarPar.View;assembly=CarPar"
            x:Class="CarPar.Navigation.NavPage"
            Title = "{Binding PageTitle}">

  <view:HomePage />
  <view:MapPage />
  <view:FavoritePage />

</TabbedPage>

HomePage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:view="clr-namespace:CarPar.View;assembly=CarPar"
             x:Class="CarPar.View.HomePage"
             Title="City"
             Icon="home.png">
    <ContentPage.ToolbarItems>
        <ToolbarItem Text="Alphabetisch" />
        <ToolbarItem Text="Freie Plätze" />
        <ToolbarItem Text="Prozent frei" />
        <ToolbarItem Text="Entfernung" />
    </ContentPage.ToolbarItems>
    <StackLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
        <SearchBar Placeholder="Parkhaus suchen" Text="{Binding SearchText}" />
    ...
    <StackLayout>
</ContentPage>

MapPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms.Maps"
             x:Class="CarPar.View.MapPage"
             Title="Karte"
             Icon="map.png">
    <ContentPage.Content>
        <StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
            <maps:Map x:Name="ParkingMap"
          IsShowingUser="True"
          MapType="Street"/>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

Answer 1

" ", . . , , - , , , , , , , AutoLayout.

    public MySecondPage()
    {
        InitializeComponent();
        NavigationPage.SetHasNavigationBar(this, false);  // Hide nav bar
    }

, , .