Currently, when inside of a Template, and keying Property changes inside of a Visual State, the changed Property creates a keyframe, but reverts to its previous value.

This appears to be a source mismatch, as refreshing the Properties Panel of the Element, seems to display the expected/desired value.

Video attached.

Repro Steps:

1) Create a Studio Project featuring a MainPage.xaml

2) Introduce a Button onto the Page, and create a new Template for it, saved to GlobalResources.
This will open the Template in the Template Dummy Editor.

3) Within the Template, navigate to the Animation Panel, and under the Visual State, select the MouseOver State.
This will open the Visual State's Timeline.

4) Select the default Content Presenter, and on the 0s mark, change its Opacity to 0%.

Observe how the keyframe is created on the Timeline, but the Opacity Property snaps back to 100%.

5) Save all open files, then close and re-open the Application.

6) Re-enter the Button Template, and navigate back to its Visual States.

7) Key any other Property change.

Observe how the Property is now changed as expected.

Expected Results: When the opacity is changed on an Element within a Template, changed Properties are registered.