如何防止绑定到TextBox的对象属性修改DataGrid的CollectionViewSource？

我已将MachineViewModel的EraNumber属性绑定至TextBox的Text属性，同时将MachineViewModel的CollectionViewSource绑定至DataGrid。当前遇到的问题是：每当修改TextBox的值时，绑定到DataGrid的CollectionViewSource中的每一项都会同步变为TextBox的新值。

相关XAML代码 #

用户控件与布局代码 #

<UserControl.DataContext>
    <Vm:MachineViewModel/>
</UserControl.DataContext>
<Grid x:Name="vehiclesGrid" Width="390" ShowGridLines="false"  >
   
    <Grid.RowDefinitions>
        <RowDefinition/>
       
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>

    <Label x:Name="lblVehicleEra" Content="Era Number"/>
      <TextBox x:Name="txtVehicleEra" Grid.Column="2"   PreviewTextInput="numbersOnly" Text="{Binding Era, NotifyOnTargetUpdated=True, NotifyOnValidationError=True, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" Style="{StaticResource TextError}" messenger:CommandBehavior.RoutedEventName="LostFocus" messenger:CommandBehavior.TheCommandToRun="{Binding EraNumberChangedCommand}" />

DataGrid代码 #

<DataGrid  x:Name="dataDisplayReport"  
                           EnableColumnVirtualization="True" 
                           EnableRowVirtualization="True" 
                           HorizontalScrollBarVisibility="Auto" 
                           HorizontalAlignment="Stretch" 
                     Grid.ColumnSpan="2" Width="Auto" 
                           AutoGenerateColumns="True"
                       ItemsSource="{Binding Source={StaticResource cvsMachines}}"
                        CanUserAddRows="False"  
                           >
                    <DataGrid.ContextMenu>
                        <ContextMenu>
                            <MenuItem Header="Update" Command="{Binding UpdateMachine}"/>
                        </ContextMenu>
                    </DataGrid.ContextMenu>
                    
            
                </DataGrid>

内容的提问来源于stack exchange，提问作者sorsa mele