InvokeActionCommand never called when using EventTriggerBehavior with Unloaded event name

[rprimora-pricer]

As per title, I am using EventTriggerBehavior with InvokeCommandAction. I am adding one behavior for both Loaded and Unloaded events. Loaded is working fine. However, the Unloaded is not. It never gets called.

I have tried using DetachedFromVisualTree and I have also tried using RoutedEventTriggerBehavior but to no avail.

Normally I have a Load and Unload commands defined in every view model. This is all hooked up as follows:

<i:Interaction.Behaviors>
   <ia:EventTriggerBeahvior EventName="Loaded">
      <ia:InvokeCommandAction Command="{Binding Load}"/>
   </ia:EventTriggerbeahvior>
   <ia:EventTriggerBeahvior EventName="Unloaded">
      <ia:InvokeCommandAction Command="{Binding Unload}"/>
   </ia:EventTriggerbeahvior>
</i:Interaction.Behaviors>

The only thing that comes as close to the unload is the following code:

<ia:EventTriggerBehavior EventName="DetachedFromVisualTree">
   <ia:InvokeCommandAction Command="{Binding DataContext.Unload, ElementName=testView}"/>
</ia:EventTriggerBehavior>

This is the project that reproduces this - UnloadedIssue.zip

When you run the project you will get a simple Window that has two buttons on the left side and content on the right. Switch the content with buttons and observer the Debug output. You should get corresponding feedback for each event. Such as:
FirstView LOADED
SecondView LOADED

If I click on First view button and then click on the Second view button I would expect the output to be as follows:
FirstView LOADED
FirstView UNLOADED
SecondView LOADED

Now comes the actual strangest part of all. This is in my own project which I cannot share here. Furthermore, I could not reproduce this behavior in the project I shared with you.
The strangest thing is that initial implementation, the one I expect to work, works on some views. This view that works also implements the Loaded and Unloaded events. As in, I have subscribed to them. This means that when the view actually loads, first the subscribed method will be called (e.g. UserControl_Loaded) after which the behavior will call my command. However, if I remove subscription to Unloaded event, behavior stops working. As I've said, I can't reproduce this though, but maybe it means something to someone.