Mouse Up Detection lost inside Scrollbox when dragging

Mouse Up Detection lost inside Scrollbox when dragging and releasing inside.
This issue occurs when trying to detect on mouse up for a scroll box

Regression:
This issue also occurs in 4.14.3

1. Create a Blank Mobile Project (Set for Mobile, Scalable 3D or 2D, No starter Content)
2. Create a Widget > Name it "Child_Widget" > Open Child_Widget
3. Delete the canvas panel in the widget > Add a Size Box
4. Change Height & Width Override to 200
5. Add a Border as a child of the Size Box
6. Go to the Event Graph and Override the On Mouse Up function
7. In the On Mouse Up function add a print string node and connect it
8. Create a New Widget > Name it "Parent_Widget" > Open Parent_Widget
9. Add a Scroll Box to the Canvas Panel > Add Child_Widget to the Scroll Box
10. Add another Child_Widget to the Canvas Panel
11. In the Level Blueprint Create the Blueprint in Screenshot_01
12. PIE and Click and drag on the Child_Widget that was a part of the canvas panel and release the mouse somewhere on the panel (Expected result)
13. Perform the same action above on the Child_Widget in the Scroll Box

Result: If click and dragged the mouse up does not print
Expected Result: Mouse up prints the string