LineAnnotation Visibility in WPF

I have configured a plot using XAML (using Plot not PlotView) with 6 LineAnnotations, which I want to show or hide optionally.

I have used Binding to connect the Visibility property of the LineAnnotations to properties in my ViewModel.

The properties are boolean and I have used a converter to convert the value to Visibility.Collapsed or Visibility.Visible (but I could just as well have defined a property with the type Visibility).

This doesn't work. The LineAnnotations are always visible.

In fact, I don't think that the Visibility property of a LineAnnotation works at all.

Is this is bug?

Is there a workaround?

Phil