Currently, when creating a Trigger Action for example, when the Action Type is changed from the default 'Change Property Action' (with its Sub-Properties expanded and revealed by default), the sub-Properties of the Action are also expanded and visible.

However, when performing the same action in the context of a Timeline Event Action, changing the Action type immediately collapses the sub-Properties.

Video Attached.

Repro Steps:

1) Create a Studio Project featuring a MainPage.xaml

2) On MainPage.xaml, navigate to the Storyboards Panel, and create a new Storyboard.

3) On the Timeline for the Storyboard, create a new Timeline Event, and select it to reveal its Properties.

4) Add an Event Action. This will produce a default ChangePropertyAction with all sub-Properties revealed.

5) Change the Action type to any other type.

Observe how the Sub-Properties collapse when the type is changed.

Expected Results: Changing Action type maintains the expanded/collapsed state previously active.