RadioButtonsControlTemplate.xaml

<ControlTemplate x:Key="CalendarRadioTemplate">
	<Frame BorderColor="#F3F2F1" BackgroundColor="#F3F2F1" HasShadow="False" 
		   HeightRequest="100" WidthRequest="100" HorizontalOptions="Start" VerticalOptions="Start" Padding="0">

		<VisualStateManager.VisualStateGroups>
			<VisualStateGroupList>
				<VisualStateGroup x:Name="CheckedStates">

					<VisualState x:Name="Checked">
						<VisualState.Setters>
							<Setter Property="BorderColor" Value="#FF3300"/>
							<Setter TargetName="Check" Property="Opacity" Value="1"/>
						</VisualState.Setters>
					</VisualState>
					
					<VisualState x:Name="Unchecked">
						<VisualState.Setters>
							<Setter Property="BackgroundColor" Value="#f3f2f1"/>
							<Setter Property="BorderColor" Value="#f3f2f1"/>
							<Setter TargetName="Check" Property="Opacity" Value="0"/>
						</VisualState.Setters>
					</VisualState>
					
				</VisualStateGroup>
			</VisualStateGroupList>
		</VisualStateManager.VisualStateGroups>

		<Grid Margin="4" WidthRequest="100">
			<Grid WidthRequest="18" HeightRequest="18" HorizontalOptions="End" VerticalOptions="Start">
				<Ellipse Stroke="Blue" WidthRequest="16" HeightRequest="16" StrokeThickness="0.5" VerticalOptions="Center" HorizontalOptions="Center" Fill="White" />
				<Ellipse x:Name="Check" WidthRequest="8" HeightRequest="8" Fill="Blue" VerticalOptions="Center" HorizontalOptions="Center" />
			</Grid>
			<ContentPresenter></ContentPresenter>
		</Grid>
	</Frame>
</ControlTemplate>

throwing the error:

Expected Setter but found Xamarin.Forms.Frame. Property not set.

When removed <VisualStateGroupList> everything becomes ok.

But selection doesn't work this way. At least for me. The RadioButton stays checked and doesn't сhange.
How did you tackle the problem?
Or it worked for you anyway?