WPF DataTrigger not firing if value remains same

I have a WPF data trigger that is set to fire when a value is true.

I want this trigger to fire everytime this value is set to true, even if it was true before. Unfortunately it seems only to fire if the value is changed from true to false or vise versa. My underlying data model is firing the PropertyChanged event of INotifyPropertyChanged even if the value is set to true twice in succession but the Trigger doesn't seem to pick this up.

Is there anyway to make the trigger run regardless of whether the bound value has changed?

Some of you have asked for the code so here it is. Interesting to note that converters will be called each time. The problem is more specific to running an animation.

Update If I change my code to reset the value to false and then back to true again it does fire the animation. Obviously this is not ideal and doesn't make the code nice to read. I'm hoping there is a better way to do this.

Any help greatly appreciated.

WPF code

<Grid>
    <Grid.Resources>            
        <Storyboard x:Key="AnimateCellBlue">
            <ColorAnimation Storyboard.TargetProperty="Background.Color" From="Transparent" To="Blue" Duration="0:0:0.1" AutoReverse="True" RepeatBehavior="1x" />
        </Storyboard>
    </Grid.Resources>
    <TextBox Name="txtBox" Text="{Binding DataContext.DisplayText, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}">           
        <TextBox.Style>
            <Style TargetType="TextBox">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding DataContext.IsTrue, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" Value="True">
                        <DataTrigger.EnterActions>                                                        
                            <BeginStoryboard Name="BidSizeUpStoryB" Stor