WPF storyboard animation changes multiple UI objects instead of one - wpf

Question

The issue
Moving styles file injection from App.xaml to view breaks animations. Instead of changing a specific element, it changes all the items with the same datatemplate.
Setup
Style.xaml:
<ResourceDictionary .....>
<Style x:Key="Style"
TargetType="{x:Type Path}">
<Style.Triggers>
<DataTrigger Binding="{Binding IsMouseOver, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Viewbox}}}"
Value="True">
<Setter Property="Fill" Value="Orange" /> <----- works as expected, changes the object that is hovered
<DataTrigger.EnterActions>
<BeginStoryboard>
<Storyboard> <----- not as expected, changes all DataModel datatemplates there is
<DoubleAnimation Storyboard.TargetProperty="RenderTransform.ScaleX"
Duration="0:0:0.2"
To="2.33" />
<DoubleAnimation Storyboard.TargetProperty="RenderTransform.ScaleY"
Duration="0:0:0.2"
To="2.33" />
</Storyboard>
</BeginStoryboard>
</DataTrigger.EnterActions>
<DataTrigger.ExitActions>
<!-- omitted, returns the default value -->
</DataTrigger.ExitActions>
</DataTrigger>
</Style.Triggers>
</Style>
<DataTemplate DataType="{x:Type DataModel}">
<Viewbox>
<Canvas Width="{Binding InitialWidth}"
Height="{Binding InitialHeight}">
<Canvas>
<Path Opacity="0.2"
x:Name="circle"
RenderTransform="{StaticResource DefaultScale}"
Style="{StaticResource Style}"> <---- the style in question
<Path.Data>
<EllipseGeometry RadiusX="{Binding Radius}"
RadiusY="{Binding Radius}" />
</Path.Data>
</Path>
<Canvas>
</Canvas>
</Viewbox>
</DataTemplate>
</ResourceDictionary>
MyView.xaml where style is used is UserControl all DataModel objects are under ItemsControl if that makes any difference.
<UserControl>
<ItemsControl VerticalAlignment="Center"
HorizontalAlignment="Center"
ItemsSource="{Binding Items}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemContainerStyle>
<Style TargetType="ContentPresenter">
<Setter Property="Canvas.Left"
Value="{Binding LeftOffset}" />
<Setter Property="Canvas.Top"
Value="{Binding TopOffset}" />
</Style>
</ItemsControl.ItemContainerStyle>
</ItemsControl>
</UserControl>
The sole change
The issue appears when moving <ResourceDictionary Source="Style.xaml" /> from App.xaml:
<Application>
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Style.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
to MyView.xaml
<UserControl>
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Style.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
</UserControl>