WPF binding ADUser doesn't update TextBox - wpf

Question

I have a WPF GUI to show AD-objects loaded and operated through PowerShell.
The GUI works as planned, but some bindings does not update their controls (mainly TextBoxes). Some controls does however work without any problem.
I get the data through the Get-AD* cmdlets and it gets stored directly in the DataContext of a Grid higher up in the hierarchy. The properties I want to list are added to the cmdlet call with -Properties "EmailAddress", .... I have also tried -Properties *, but the bindings still doesn't update.
I suspect that only the properties that are inherited from the baseobject, works with the bindings. But I can be totaly of on this.
I have tried:
different settings for the binding, i.e. NotifyOnSourceUpdate...
separating the properties through Select-Object EmailAddress, ..., but this breaks it all and no controls are shown
using a test object (PSCustomObject) with the necessary properties, this also break the controls
if I assign the values directly in code, the textboxes show the correct info, i.e. $syncHash.tbUserotherTelephone.Text = $syncHash.gridObjInfo.DataContext.otherTelephone
For the example below, the object that is put in $syncHash.gridBaseInfoUser.DataContext is of type ADUser (BaseType: Microsoft.ActiveDirectory.Management.ADAccount)
Exampel of how the object the bindings are sourced from, is retrieved
$syncHash.gridObjInfo.DataContext = Get-ADUser $this.SelectedItem -Properties "EmailAddress", ...
$this.SelectedItems is the selected item in a DataGrid. I have verified that the correct data is retrieved at both Get-ADUser
Xaml hierarchy, showing two controls, one that gets the TextBox.Text entered, one that doesn't. Some code is omitted to save space.
<Window>
<Grid x:Name="gridMain">
...
<Grid x:Name="gridMainInfo" Grid.Row="1" DockPanel.Dock="Top" Width="Auto">
<Grid x:Name="gridObjInfo">
<Grid.Resources>
<Style x:Key="PropValueStyle" TargetType="{x:Type TextBox}">
<Setter Property="Grid.Column" Value="1"/>
<Setter Property="IsEnabled" Value="True"/>
<Setter Property="IsReadOnly" Value="True"/>
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=Text}" Value="">
<Setter Property="Background" Value="LightGray"/>
</DataTrigger>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=Text}" Value="{x:Null}">
<Setter Property="Background" Value="LightGray" />
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Resources>
<!-- Other grids for other objectclasses -->
<Grid x:Name="gridBaseInfoUser" Grid.Row="{DynamicResource TypeObjInfoRowLoc}">
<Grid.Style>
<Style TargetType="{x:Type Grid}">
<Setter Property="Visibility" Value="Collapsed"/>
<Style.Triggers>
<DataTrigger Binding="{Binding ObjectClass}" Value="user">
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Grid.Style>
<!-- This binding apparently does not work, so the textbox is empty -->
<Border Style="{StaticResource PropBorder}" Grid.Row="5">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{StaticResource PropTitleWidth}"/>
<ColumnDefinition Width="{StaticResource PropValueWidth}"/>
</Grid.ColumnDefinitions>
<TextBlock x:Name="tblUserotherTelephone" Style="{StaticResource PropTitleStyle}"/>
<TextBox x:Name="tbUserotherTelephone" Style="{StaticResource PropValueStyle}" Text="{Binding otherTelephone}"/>
</Grid>
</Border>
<!-- This binding apparently does work, so the textbox gets its Text set to the UserPrincipalName -->
<Border Style="{StaticResource PropBorder}" Grid.Row="6">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{StaticResource PropTitleWidth}"/>
<ColumnDefinition Width="{StaticResource PropValueWidth}"/>
</Grid.ColumnDefinitions>
<TextBlock x:Name="tblUserUserPrincipalName" Style="{StaticResource PropTitleStyle}"/>
<TextBox x:Name="tbUserUserPrincipalName" Style="{StaticResource PropValueStyle}" Text="{Binding UserPrincipalName}"/>
</Grid>
</Border>
</Grid>
...
</Window>