Cannot dynamically change when pressed sound for buttons in UMG

Cannot change the when pressed sound for the style of a button in umg via the set style node.

Reopened after the report from: https://udn.unrealengine.com/questions/273621/setting-widgetstyle-for-button-doesnt-change-the-c.html#answer-273629

1. Open Editor
2. Create a new widget blueprint
3. Open widget blueprint
4. Add button to the designer tab
5. Go to the event graph
6. Create the blueprint in the attached image
7. Compile and save
8. Open level blueprint
9. Add the widget to the view port on begin play
10. Play in editor
11. Notice that no sound plays

Expected: Sound would be set and played when the button was clicked
Result: The sound is not set

Changing button style does not change pressed sound