Datatrigger no longer working with binding to Picker and SelectedItem

[clEclE36]

Actually :

• .NET MAUI 8.0.70
• CommunityToolkit.Mvvm 8.2.2
• CommunityToolkit.Maui 9.0.2

Worked before with :

• .NET MAUI 8.0.61
• CommunityToolkit.Mvvm 8.2.2
• CommunityToolkit.Maui 9.0.1

To summarize, I have a CollectionView that is bound to a list of Anomaly objects (line 206, ItemsSource="{Binding Anomalies}") and whose display depends on the content of an attribute of my Anomaly object.
The attribute in question is a list of Defaults (line 94 ItemsSource="{Binding Defaults}".
If the list is empty, I display a checkbox, otherwise I display a Picker to select a Default.

To manage this, I have a resource with a personal DataTemplateSelector, AlertTemplateSelector.

Now we come to the problem in question!

I've set up the following behavior: when the user checks a box or selects a Default, the Anomaly Label is italicized and bolded.
I therefore have Label.Triggers on lines 29-42 (for the CheckBox) and 78-86 (for the Picker).

No errors at compile time.
But when loading the view, I get a "System.Reflection.TargetInvocationException: 'Exception has been thrown by the target of an invocation.'"

After a few empirical tests, the problem comes solely from the Picker and more precisely from the Label.Triggers.
If I remove the Label.Triggers from the Picker, the View loads.

I've also tried modifying the Converter using a custom one instead of the Toolkit one, but it doesn't even fit.

I also tried binder on another Path. Instead of SelectedItem, I binded on Text.Length and Value at 0 without Converter.
For debugging and hot reloading, I changed the Picker's Title value in the XAML to "" (empty) and the View loads and the trigger works: the Label's text changes to bold italics when I empty the Title value.

The problem comes from the binding on the SelectedItem.

Does anyone have any idea what's going on?
Did I miss a note in the release about the bindings requirement?

The following code of the View worked with previous versions of Maui and the above-mentioned Nugets packages:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:mct="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
    xmlns:views="clr-namespace:******.Views"
    xmlns:viewmodels="clr-namespace:******.ViewModels"
    xmlns:models="clr-namespace:******.Models"
    xmlns:helpers="clr-namespace:******.Helpers"
    xmlns:datatemplatesselectors="clr-namespace:******.DataTemplatesSelectors"
    x:Class="******.Views.SelectAlertsView"
    x:DataType="viewmodels:SelectAlertsViewModel">

    <ContentPage.Resources>
        <DataTemplate x:Key="CheckBoxTemplate"
                      x:DataType="models:Anomaly">
            <Grid RowDefinitions="Auto"
                  ColumnDefinitions="1*, 1*"
                  ColumnSpacing="1"
                  Padding="2, 5">
                <Label Grid.Column="0"
                       Text="{Binding Label}"
                       LineBreakMode="WordWrap"
                       ToolTipProperties.Text="{Binding Label}"
                       HorizontalOptions="Fill"
                       VerticalOptions="Fill"
                       HorizontalTextAlignment="Start"
                       VerticalTextAlignment="Center">
                    <Label.Triggers>
                        <DataTrigger TargetType="Label"
                                     Binding="{Binding Source={x:Reference checkbox}, Path=IsChecked}"
                                     Value="true">
                            <Setter Property="FontAttributes"
                                    Value="Italic, Bold" />
                        </DataTrigger>
                    </Label.Triggers>
                    <Label.GestureRecognizers>
                        <TapGestureRecognizer NumberOfTapsRequired="1"
                                          Command="{Binding BindingContext.ToggleCheckBoxCommand, Source={x:Reference anomalies_collection}}"
                                          CommandParameter="{x:Reference checkbox}"/>
                    </Label.GestureRecognizers>
                </Label>
                <CheckBox Grid.Column="1"
                          x:Name="checkbox"
                          HorizontalOptions="Center"
                          VerticalOptions="Center"
                          Color="{StaticResource Primary}">
                    <CheckBox.Behaviors>
                        <mct:EventToCommandBehavior EventName="CheckedChanged"
                                                    Command="{Binding BindingContext.UpdateCheckedAnomaliesCommand, Source={x:Reference anomalies_collection}}">
                            <mct:EventToCommandBehavior.CommandParameter>
                                <MultiBinding Converter="{StaticResource AnomalyConverter}">
                                    <MultiBinding.Bindings>
                                        <Binding Path="IsChecked" Source="{x:Reference checkbox}" />
                                        <Binding Path="."/>
                                    </MultiBinding.Bindings>
                                </MultiBinding>
                            </mct:EventToCommandBehavior.CommandParameter>
                        </mct:EventToCommandBehavior>
                    </CheckBox.Behaviors>
                </CheckBox>
            </Grid>
        </DataTemplate>
        <DataTemplate x:Key="PickerTemplate"
                      x:DataType="models:Anomaly">
            <Grid RowDefinitions="Auto"
                  ColumnDefinitions="50*, 45*, 5*"
                  ColumnSpacing="1"
                  Padding="2, 5">
                <Label Grid.Column="0"
                       Text="{Binding Label}"
                       LineBreakMode="WordWrap"
                       ToolTipProperties.Text="{Binding Label}"
                       HorizontalOptions="Fill"
                       VerticalOptions="Fill"
                       HorizontalTextAlignment="Start"
                       VerticalTextAlignment="Center">
                    <Label.Triggers>
                        <DataTrigger TargetType="Label"
                                     Binding="{Binding Source={x:Reference picker}, Path=SelectedItem, Converter={StaticResource IsNotNullConverter}}"
                                     Value="true">
                            <Setter Property="FontAttributes"
                                    Value="Italic, Bold" />
                        </DataTrigger>
                    </Label.Triggers>
                </Label>
                <Picker Grid.Column="1"
                        x:Name="picker"
                        Title="Choisir un défaut"
                        HorizontalOptions="Fill"
                        VerticalOptions="Fill"
                        HorizontalTextAlignment="Center"
                        VerticalTextAlignment="Center"
                        ItemsSource="{Binding Defaults}"
                        ItemDisplayBinding="{Binding Label}">
                    <Picker.Behaviors>
                        <mct:EventToCommandBehavior EventName="SelectedIndexChanged"
                                                    Command="{Binding BindingContext.UpdateSelectedAnomaliesCommand, Source={x:Reference anomalies_collection}}">
                            <mct:EventToCommandBehavior.CommandParameter>
                                <MultiBinding Converter="{StaticResource AnomalyConverter}">
                                    <MultiBinding.Bindings>
                                        <Binding Path="SelectedItem" Source="{x:Reference picker}" />
                                        <Binding Path="."/>
                                    </MultiBinding.Bindings>
                                </MultiBinding>
                            </mct:EventToCommandBehavior.CommandParameter>
                        </mct:EventToCommandBehavior>
                    </Picker.Behaviors>
                </Picker>
                <ImageButton Grid.Column="2"
                             Source="close_cross.png"
                             HorizontalOptions="Center"
                             VerticalOptions="Center"
                             WidthRequest="24"
                             HeightRequest="24"
                             IsVisible="{Binding Source={x:Reference picker}, Path=SelectedItem, Converter={StaticResource IsNotNullConverter}}"
                             Command="{Binding BindingContext.UnselectSelectedAnomalyCommand, Source={x:Reference anomalies_collection}}">
                    <ImageButton.CommandParameter>
                        <MultiBinding Converter="{StaticResource AnomalyConverter}">
                            <MultiBinding.Bindings>
                                <Binding Source="{x:Reference picker}" Path="." />
                                <Binding Path="."/>
                            </MultiBinding.Bindings>
                        </MultiBinding>
                    </ImageButton.CommandParameter>
                    <ImageButton.Behaviors>
                        <mct:IconTintColorBehavior TintColor="{StaticResource DangerColor}"/>
                    </ImageButton.Behaviors>
                </ImageButton>
            </Grid>
        </DataTemplate>

        <datatemplatesselectors:AlertTemplateSelector x:Key="AlertTemplateSelector"
                                                      CheckBoxTemplate="{StaticResource CheckBoxTemplate}"
                                                      PickerTemplate="{StaticResource PickerTemplate}" />
    </ContentPage.Resources>

    <Shell.TitleView>
        <FlexLayout Direction="Row"
                    AlignItems="Center"
                    JustifyContent="SpaceBetween">
            <Label Text="{Binding ShellTitleValue, Mode=OneWay}"
                   HorizontalTextAlignment="Start"
                   VerticalTextAlignment="Center"
                   LineBreakMode="MiddleTruncation"
                   TextColor="{StaticResource WhiteColor}"/>
            <VerticalStackLayout HorizontalOptions="End"
                                 VerticalOptions="Fill"
                                 WidthRequest="32"
                                 Margin="{OnPlatform '10, 0, 5, 0', iOS='10, 0, 0, 0'}">
                <ImageButton Source="back_menu.png"
                             HorizontalOptions="End"
                             VerticalOptions="Fill"
                             HeightRequest="32"
                             ToolTipProperties.Text="Retour au menu"
                             Command="{Binding CancelAlertsCommand}">
                    <ImageButton.Behaviors>
                        <mct:IconTintColorBehavior TintColor="{StaticResource WhiteColor}" />
                    </ImageButton.Behaviors>
                </ImageButton>
            </VerticalStackLayout>
        </FlexLayout>
    </Shell.TitleView>

    <Grid x:Name="anomalies_panel"
          IsVisible="True"
          Margin="0"
          Padding="0"
          ColumnSpacing="2"
          RowSpacing="5"
          ColumnDefinitions="*, *"
          RowDefinitions="Auto, Auto, *, Auto">
        <VerticalStackLayout Grid.Row="0"
                             Grid.ColumnSpan="2">
            <Label Text="{Binding TitleLabel}"
                   Style="{StaticResource TitleLabelStyle}"
                   HorizontalOptions="Fill"
                   VerticalOptions="Fill"
                   HorizontalTextAlignment="Center"
                   VerticalTextAlignment="Center">
            </Label>
            <Border BackgroundColor="{StaticResource SeparatorLineColor}" Margin="10, 0"/>
        </VerticalStackLayout>
        <Label Grid.Row="1"
               Grid.ColumnSpan="2"
               HorizontalOptions="Fill"
               VerticalOptions="Fill"
               HorizontalTextAlignment="Start"
               VerticalTextAlignment="Center"
               Margin="15, 0"
               Style="{StaticResource SubTitleLabelStyle}"
               Text="{Binding Alerts.Count, StringFormat='Anomalies signalées : {0}'}"/>
        <Border Grid.Row="2"
                Grid.ColumnSpan="2"
                Margin="5, 0"
                HorizontalOptions="Fill"
                VerticalOptions="Fill"
                Stroke="{StaticResource LightBorderColor}"
                BackgroundColor="Transparent"
                IsVisible="True">
            <Border.StrokeShape>
                <RoundRectangle CornerRadius="10,10,10,10" />
            </Border.StrokeShape>
            <CollectionView x:Name="anomalies_collection"
                            Margin="5, 0"
                            ItemsSource="{Binding Anomalies}"
                            ItemTemplate="{StaticResource AlertTemplateSelector}"
                            SelectionMode="None">
            </CollectionView>
        </Border>
        <Button Grid.Row="3"
                Grid.ColumnSpan="2"
                x:Name="validate_button"
                Text="Valider"
                VerticalOptions="End"
                BackgroundColor="{Binding Source={RelativeSource Self}, Path=IsEnabled, Converter={StaticResource ValidatedColorConverter}}"
                Command="{Binding ValidateCommand}"
                IsEnabled="{Binding Alerts.Count, Converter={StaticResource CountToBoolConverter}}">
        </Button>
        <!-- ActivitiIndicator -->
        <ActivityIndicator Grid.Row="2"
                           Grid.ColumnSpan="2"
                           Color="{StaticResource LightGreenColor}"
                           IsRunning="{Binding IsBusy}"
                           IsVisible="{Binding IsBusy}"
                           VerticalOptions="Center"
                           HorizontalOptions="Center">
            <ActivityIndicator.WidthRequest>
                <OnPlatform x:TypeArguments="x:Double">
                    <On Platform="iOS, Android" Value="100" />
                    <On Platform="WinUI" Value="400" />
                </OnPlatform>
            </ActivityIndicator.WidthRequest>
        </ActivityIndicator>
    </Grid>
    
</ContentPage>