Piechart 's CenterText not updating from ViewModel

[viveknegi51288]

<custom:CustomPieChart BackgroundColor="Red" CenterText="{Binding SelectedCategoryTotalAmount}" x:Name="pieChart" RotateEnabled="False" HeightRequest="180" WidthRequest="180" ExtraTopOffset="0" ExtraBottomOffset="0" TransparentCircleRadiusPercent="0" HighLightPerTapEnabled="False" HorizontalOptions="FillAndExpand"

                                           ChartData="{Binding SalaryData}" VerticalOptions="FillAndExpand"  />

I am able to Set ChartData from ViewModel (from SalaryData list from ViewModel).. which is showing the piechart data as expected but CenterText (SelectedCategoryTotalAmount variable in viewModel) but nothing is updated.

public string CenterTextDescription { get => _centerTextDescription; set { SetProperty(ref _centerTextDescription , value); } }

I am using prism framework