Grid column width not respected when inside of a ScrollViewer - wpf

Question

I've one view of mine which displays a control based on some factory:
<dxdo:LayoutPanel ShowCaption="False">
<ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">
<ContentControl Margin="15,5,10,10" Content="{Binding SomeObject, Converter={StaticResource ModelToViewModelConverter}}" ContentTemplateSelector="{StaticResource ConventionBasedDataTemplateSelector}" />
</ScrollViewer>
</dxdo:LayoutPanel>
One of the control that is displayed contains one Grid, with some specific controls.
Basically I've the 2 firsts columns that are used with specific sizes and a third one to take the remaining available space, and then some components that takes the whole width:
<UserControl x:Class="ch.VibroMeter.Xms.Configurators.Common.Views.Machinery.MachineStates.CustomMachineStateView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
<!-- skipping namespace declaration -->
mc:Ignorable="d" >
<UserControl.Resources>
<converters:DrawingColorToMediaColorConverter x:Key="DrawingColorToMediaColorConverter" />
</UserControl.Resources>
<StackPanel>
<controls:TitleBlock Title="{Binding State.Name}" Margin="0,0,0, 5" />
<subControls:MainProperties Model="{Binding State, ValidatesOnNotifyDataErrors=False}" />
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{Binding Source={x:Static common:Constants.COLUMN_LABEL_WIDTH}}" />
<ColumnDefinition Width="{Binding Source={x:Static common:Constants.COLUMN_FIELD_WIDTH}}" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<!--Color-->
<TextBlock Grid.Row="0" Grid.Column="0" Text="Color" Margin="3" />
<dxe:PopupColorEdit Grid.Row="0" Grid.Column="1" ShowAlphaChannel="False" Margin="3" Color="{Binding State.Color, Mode=TwoWay, Converter={StaticResource DrawingColorToMediaColorConverter}}" />
<!--Separator-->
<Separator Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" Margin="0,12,0,12"/>
<!--Measurements Filters -->
<TextBlock Grid.Row="2" Grid.Column="0" Text="Conditions" FontSize="18" Margin="3,3,3,12"/>
<measurementsFilterConfigurationControl:MeasurementsFilterConfigurationControl Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="3"
FilterRuleTypes="{Binding AvailableFilterRuleTypes}"
MeasurementsFilterConfiguration="{Binding State.FilterConfiguration}"
Margin="0 10 0 0"/>
</Grid>
</StackPanel>
</UserControl>
I found out that the columns sizes are not at all respected. The COLUMN_LABEL_WIDTH is 200, but the ActualWidth of my TextBlock with "Color" text is more than 300.
After some investigation, I found out that if I remove the ScrollViewer or set the HorizontalScrollBarVisibility to Disabled, it works, but then when I resize the window too much(for this control, less than COLUMN_LABEL_WIDTH +COLUMN_FIELD_WIDTH), I don't get the desired scrollbars.
I understand that when I use a scrollViewer, I will get an infinite available size, but I would have thought this space would have been put in the column with the * size.
I cannot removing the scrollViewer Auto, because some components(like the MeasurementsFilterConfigurationControl in this view) might get hidden when resizing the windows).
I don't have access to the ScrollViewer in this component.
So how would you fix this?