Currently, we offer the ability to simultaneously edit the Properties of multiple Elements at once.
However, this feature only appears to apply if the Elements are multi-selected from the Navigator.
If they are multi-selected from the Storyboard's Timeline however, only the first selected Element will have its Property changed.

Repro Steps:

1) Download and open the attached Studio Project.

2) In the Navigator, identify the UserControl named "TopographicPattern_UserControl" (found under the "Foreground_Group_Grid" Grid under the RootGrid.

3) Enter the TopographicPattern_UserControl's context menu, and open the UserControl's Template for Edit
This will then open in the dummy Template Editor.

4) Within the UserControl Template, navigate to the Animation/Storyboards Panel, and select the Storyboard named "TopoPattern_Animation".
This will open the Timeline, where you will see 60 Paths with their Opacity values keyed out, with all of them ending at 100% Opacity at the 7s mark.

5) Drag the Playhead to the 8s mark on the Timeline/

6) With the Playhead still at the 8s mark, click on the first Element in the Timeline (Path0), then hold Shift, and select the last Element in the Timeline (Path59.
This will select Path0, Path59. and all Elements between them.

7) With all Elements selected, and with the Playhead at the 8s mark, adjust the Opacity value to 0%.

Observe how a keyframe is only added for Path0, and not for all other Elements.

8) In the Navigator, identify, and expand the Grid named "TopoPattern_Animated_Grid", and similarly to how performed in Step 6), selected all Elements between Path0 and Path59.

9) Then, similarly to Step 7), at the 8s mark, adjust the Opacity of all Elements to 0%.

Observe how Keyframes are created for all of the selected Elements.

Expected Results: Elements multi-selected from the Timeline offer the same features as those multi-selected from the Navigator.