Currently, there is an issue where when certain Keyframe Categories are selected in a Timeline, the Properties Panel momentarily flashes Interpolation Properties, before the panel clears.

See attached video.

Repro Steps:

1) Open the MiniShowcases Studio project from the InternalProjects GitHub, and open Interpolation.xaml

2) With Interpolation.xaml open, navigate to its Animation/Storyboard Panel, and identify, then select the 'Animation_FlyingKites' Storyboard.
This will open the Storyboard's timeline in the bottom-centre of the application window.

3) Within the Storyboard Timeline, identify the StackPanel named 'KiteAndString_Girl_INTERPOLATED', and click its name within the Timeline.
Observe how it displays a full Properties Panel for the Element.

4) In the Timeline, expand all sub-lines of the 'KiteAndString_Girl_INTERPOLATED'.
This should reveal a: 'RenderTransform' line, a 'Rotation' line, and an 'Angle' line.

5) Working down the list from 'KiteAndString_Girl_INTERPOLATED' until 'Angle', click the name of each line sequentially.

Observe how the 'RenderTransform' and 'Rotation' selections will flash content in the Properties Panel momentarily, before disappearing.

Expected Results: If no content is meant to display in the Properties Panel, it should not display at any point.