public bool showHomeworkIcon { get; set; }

public override IAppointment Copy()
{
    var task = new kmdAppointment();
    task.CopyFrom(this);
    return task;
}

public override void CopyFrom(IAppointment other)
{
    var task = other as kmdAppointment;
    if (task != null)
    {
        this.Rooms = task.Rooms;
        this.attachments = task.attachments;
        this.Teachers = task.Teachers;
        this.Description = task.Description;
        this.SubjectCourses = task.SubjectCourses;
        this.IsCancelled = task.IsCancelled;
        this.AppointmentColor = task.AppointmentColor;
        this.AppointmentSecondaryColor = task.AppointmentSecondaryColor;
        this.homeworkList = task.homeworkList;
        this.LessonAssignment = task.LessonAssignment;


        this.hasHomework = task.hasHomework;
        this.startEndString = task.startEndString;
        this.showHomeworkIcon = task.showHomeworkIcon;
        this.showLessonAssignmentIcon = task.showLessonAssignmentIcon;
    }
    base.CopyFrom(other);
}

 <telerik:RadBorder CornerRadius="4"
                    Margin="1"
                    IsClippedToBounds="True"
                    BorderBrush="{Binding Occurrence.Appointment.AppointmentSecondaryColor}"
                    BorderThickness="4,0,0,0"
                    BackgroundColor="{Binding Occurrence.Appointment.AppointmentColor}">
     <Grid RowSpacing="0">
         <Grid.RowDefinitions>
             <RowDefinition Height="auto"></RowDefinition>
             <RowDefinition Height="auto"></RowDefinition>
             <RowDefinition Height="auto"></RowDefinition>
             <RowDefinition Height="*"></RowDefinition>
             <RowDefinition Height="auto"></RowDefinition>
         </Grid.RowDefinitions>
         <Grid.ColumnDefinitions>
             <ColumnDefinition Width="*"></ColumnDefinition>
             <ColumnDefinition Width="Auto"></ColumnDefinition>
             <ColumnDefinition Width="Auto"></ColumnDefinition>
         </Grid.ColumnDefinitions>

<label Grid.Row="0"
Grid.ColumnSpan="3"/> //repeat labels for 1,3 2,3 and 4,3. 3 is * to force the rows below to be near the end.


     <Image  Grid.Row="4"
         Grid.Column="1"
     </Image>

     <Image Grid.Row="4"
                           Grid.Column="2"
                           Margin="4, 0, 4, 4"
                           IsVisible="{Binding Occurrence.Appointment.showHomeworkIcon}">
                        <Image.Source>
                            <FontImageSource FontFamily="Material"
                                             Glyph="{x:Static materialDesign:MaterialDesignIcons.BookOpenBlankVariantOutline}"
                                             Color="{StaticResource BrandPrimary}"
                                             Size="16" />
                        </Image.Source>
      </Image>
  </Grid>
</telerik:RadBorder>

ScrollItemIntoView(item, false)

System.IndexOutOfRangeException

Message: Arg_IndexOutOfRangeException
Telerik.Maui.Data.IndexStorage.ValueForIndex(Int32 index, Boolean approximate)
Telerik.Maui.Controls.RadCollectionView+<ScrollIndexIntoView>d__170.MoveNext()
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task, ConfigureAwaitOptions options)
Telerik.Maui.Controls.RadCollectionView+<>c__DisplayClass168_0+<<ScrollIndexIntoViewCore>b__0>d.MoveNext()
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
System.Threading.Tasks.Task+<>c.<ThrowAsync>b__128_0(Object state)
Android.App.SyncContext+<>c__DisplayClass2_0.<Post>b__0()
Java.Lang.Thread+RunnableImplementor.Run()
Java.Lang.IRunnableInvoker.n_Run(IntPtr jnienv, IntPtr native__this)
Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PP_V(_JniMarshal_PP_V callback, IntPtr jnienv, IntPtr klazz)

<ContentPage>
    <Grid RowDefinitions="Auto, *">
        <telerik:RadPdfViewerToolbar x:Name="pdfViewerToolbar"
                                     OverflowMode="Scroll"
                                     PdfViewer="{x:Reference pdfViewer}">
            <telerik:PdfViewerFitToWidthToolbarItem />
            <telerik:PdfViewerNavigateToPreviousPageToolbarItem />
            <telerik:PdfViewerNavigateToNextPageToolbarItem />
            <telerik:PdfViewerZoomInToolbarItem />
            <telerik:PdfViewerZoomOutToolbarItem />
            <telerik:PdfViewerSearchNavigationToolbarItem />
            <telerik:PdfViewerToggleLayoutModeToolbarItem />
        </telerik:RadPdfViewerToolbar>
        <telerik:RadPdfViewer x:Name="pdfViewer"
                              Grid.Row="1"
                              AutomationId="pdfViewer"
                              BackgroundColor="{StaticResource White}"
                              IgnoreSafeArea="False"
                              IsClippedToBounds="True"                              
                              LayoutMode="ContinuousScroll"
                              Source="{Binding PdfFile}" />
    </Grid>
</ContentPage>