Repro Steps:

1) Create a Page
2) Navigate to the Interactivity/Triggers Panel.
3) Select the Root Grid of the page
4) Create a first DataTrigger applied to the Root Grid.
5) Press the "Add Trigger" button again to add a second DataTrigger to the Root Grid.

Observe how the second Trigger does not get added.

6) Select any other element, (for example, the Page in the Navigator).
7) Return to the Root Grid, and attempt to add a DataTrigger.

Observe how a second DataTrigger was succesfully added.

Expected Results: Multiple DataTriggers can be added in sequence without clicking on another element first.