CollectionView: EmptyView content not shown - xamarin.forms

Question

I have a bug in the page display using a listview so I started migrating from listview to collectionview, but...
This is the XAML code with the collection View, I dont know why when the ItemSource dont have any data, the empty view is not shown.
<StackLayout Style="{StaticResource PageLayout}">
<StackLayout VerticalOptions="CenterAndExpand" IsVisible="{Binding LoadingIndicator}">
<ActivityIndicator IsRunning="True" VerticalOptions="Center" HorizontalOptions="Center"/>
</StackLayout>
<StackLayout VerticalOptions="FillAndExpand" IsVisible="{Binding ShowContent}">
<CollectionView ItemsSource="{Binding Items}" VerticalOptions="FillAndExpand" SelectionMode="Single" SelectionChanged="CollectionView_SelectionChanged" Style="{StaticResource CollectionViewChecklistDefault}">
<CollectionView.Header>
<StackLayout HeightRequest="5">
</StackLayout>
</CollectionView.Header>
<CollectionView.ItemTemplate>
<DataTemplate>
<Grid ColumnSpacing="0" RowSpacing="0" Margin="0" Padding="0">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="25" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="40" />
<RowDefinition Height="10" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="37*" />
<ColumnDefinition Width="33*" />
<ColumnDefinition Width="30*" />
</Grid.ColumnDefinitions>
<Label Grid.Row="0" Grid.Column="1" Text="{Binding APP_ID}" IsVisible="False"/>
<BoxView Grid.Row="0" Grid.Column="0" Grid.RowSpan="8" Grid.ColumnSpan="3" Style="{StaticResource ListBox}"/>
<Image Grid.Row="0" Grid.Column="0" Aspect="AspectFit" Style="{StaticResource ListImage}">
<Image.Source>
<FontImageSource Glyph="" FontFamily="FontAwesomeSolid" Color="#343a40"></FontImageSource>
</Image.Source>
</Image>
<Label Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2" Text="{Binding OBSERVATION_TYPE_NAME}" Style="{StaticResource ListLabelBold}"/>
<Label Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource PreviewLabel}">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Traductions[DATE], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}, StringFormat='\{0}:'}" FontAttributes="Bold" TextTransform="Uppercase" TextColor="DarkGray"/>
<Span Text="{Binding OBSERVATION_DATE, StringFormat=' \{0:dd MMM yyyy}'}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Label Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource PreviewLabel}">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Traductions[COMPANY], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}, StringFormat='\{0}: '}" FontAttributes="Bold" TextTransform="Uppercase" TextColor="DarkGray"/>
<Span Text="{Binding COMPANY_NAME, StringFormat=' \{0}'}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Label Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource PreviewLabel}">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Traductions[WORKPLACE], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}, StringFormat='\{0}: '}" FontAttributes="Bold" TextTransform="Uppercase" TextColor="DarkGray"/>
<Span Text="{Binding WORKPLACE_NAME, StringFormat=' \{0}'}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Label Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource PreviewLabel}">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Traductions[SECTOR], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}, StringFormat='\{0}: '}" FontAttributes="Bold" TextTransform="Uppercase" TextColor="DarkGray"/>
<Span Text="{Binding SECTOR_NAME, StringFormat=' \{0}'}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Label Grid.Row="5" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource PreviewLabel}">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Traductions[FOLLOW_UP_DEPARTMENT], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}, StringFormat='\{0}: '}" FontAttributes="Bold" TextTransform="Uppercase" TextColor="DarkGray"/>
<Span Text="{Binding FOLLOW_DEPARTMENT_NAME, StringFormat=' \{0}'}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Label Grid.Row="6" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource PreviewLabel}">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Traductions[DESCRIPTION], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}, StringFormat='\{0}: '}" FontAttributes="Bold" TextTransform="Uppercase" TextColor="DarkGray"/>
<Span Text="{Binding OBSERVATION_DESCRIPTION, StringFormat=' \{0}'}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Label Grid.Row="7" Grid.Column="0" Grid.ColumnSpan="3" Text="{Binding Traductions[CLOSE_OBSERVATION], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}}" Style="{StaticResource ListValueGreenEnd}" />
<Image Grid.Row="7" Grid.Column="2" Aspect="AspectFit" Style="{StaticResource ListImageArrow}">
<Image.Source>
<FontImageSource Glyph="" FontFamily="FontAwesomeSolid" Color="#7ca04b"></FontImageSource>
</Image.Source>
</Image>
</Grid>
</DataTemplate>
</CollectionView.ItemTemplate>
<CollectionView.EmptyView>
<StackLayout VerticalOptions="CenterAndExpand">
<Label Text="{Binding Traductions[THERE_ARE_NO_OBSERVATIONS], Source={RelativeSource AncestorType={x:Type viewModel:ObservationCloseListViewModel}}}" Style="{StaticResource ListNotItemsFound}"/>
<Label Text="TEST"/>
</StackLayout>
</CollectionView.EmptyView>
</CollectionView>
</StackLayout>
</StackLayout>
This is how it shows with collection view (empty). I put an extra label with TEST
This is how it has to be

Answer 1

The root cause of the issue you faced lays in usage of CollectionView.Header. But that's not your mistake. It is a bug of CollectionView: EmptyView does not appear when Header is used.
It had been already reported to Xamarin.Forms developers. You can track the progress here.

Answer 2

I did some experiments. The only way I can get this symptom to happen is if {Binding ShowContent} fails to return True.
I believe the problem isn't the CollectionView. Its the visibility of the surrounding StackLayout.
To verify:
Replace IsVisible="{Binding ShowContent}" with IsVisible="True".
If that makes EmptyView show up, then check these possible causes:
BindingContext. (In a comment, you show what looks like correct code. Double-check.)
Proper declaration of ShowContent, to inform XAML of changes:
// Start "true", so InitializeComponent will begin with it there.
private bool _showContent = true;
public bool ShowContent {
get => _showContent;
set {
_showContent = value;
OnPropertyChanged();
}
}
If you have code that sets ShowContent, verify that you have set it to true.