https://learn.microsoft.com/pt-br/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.data.bindingexpression.updatesource?view=windows-app-sdk-2.0
BindingExpression.UpdateSource Method (Microsoft.UI.Xaml.Data) - Windows App SDK | Microsoft Learn
Sends the current binding target value to the binding source property in TwoWay bindings.
windows appmethodmicrosoftui