Calling SetNavigationRule for widgets at runtime does not update the Nav Rule

Calling SetNavigationRule at runtime does not update the widget navigation of the selected widget.

Regression:
No - same behavior occurs in 4.16.3 (CL 3561208)

1. Open UE4 Editor (any project)
2. In Project Settings > Engine > User Interface, set Render Focus Rule to Always
3. In Content Browser add widget blueprint (MyWidget)
4. Add three buttons to MyWidget in a line (named Button1, Button2, Button3 from left to right)
5. In the Level Blueprint, add Event BeginPlay > Create Widget
6. Add two nodes from Create Widget return value (Add to Viewport & Set Navigation Rule)
7. Connect "Add to Viewport" exec & Target input pins to "Create Widget" exec & Return Value output pins
8. Add Event KeyPress (Y) > SetNavigationRule
9. Set the SetNavigationRule Target to Button1 (drag off of Create Widget return value to get reference)
10. Set Widget to Focus to Button3
    (see attached screenshot for steps 5-10)
11. PIE
12. Shift+F1 to to get the mouse cursor
13. Click Button3 (right most) and use the left arrow key to navigate through the buttons

Result:
Focus changes from Button3 to Button2, then to Button1 but then stops

Expected:
Pressing Left arrow while Button1 has focus changes focus to Button3