Bindings are broken in SplitView

[TheCamel]

Bindings are broken in SplitView

I had a form that was working...and to replace a dialog, i included all the form content in the SplitView and put the dialog in the pane. All was working till we saw that all previous bindings are broken, also the {Binding ElementName= ??

Steps to reproduce

Take the actual demo form, add bindings between 2 elements

 <Grid Background="CornflowerBlue">
     <TextBlock Margin="10"
                HorizontalAlignment="Stretch"
                VerticalAlignment="Stretch"
                FontSize="20"
                Foreground="Black"
                Text="{Binding ElementName=test, Path=Value}"
                 />
     <Slider x:Name="test" Minimum="0" Maximum="100"></Slider>
 </Grid>

run it, try find the binding error in the output logs

System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=test'. BindingExpression:Path=Value; DataItem=null; target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String')

Environment

MahApps.Metro version: v3.0.0 alpha0476
Target Framework: Core 8

Screenshots