Set Content for Slot does not override the current value that is in a named slot widget

The function Set Content for Slot does not appear to be overriding the old value when trying to set a new value for the named slot. The user has to pass in a null value before the function will set a new value to the named slot widget

1. Download attached project
2. Open and generate project files
3. Open "NewMap"
4. Play in Editor
5. Click the button
6. Notice that the text does not change (the text to the left of the button)
7. Stop PIE
8. Open MainMenu widget
9. Hook up the two nodes within the comment boxes in the event graph (attached image for reference)
10. Play in Editor
11. Click the button
12. Notice that the text changes now

Expected: The Set Content for slot would override the content that was already applied to the named slot
Result: The Set Content for Slot needs to be passed a null value before it will override the old value