Steps to reproduce:
1. Open the project and the scene "gui event testing"
2. Play the scene
3. Press the scroll wheel button, scroll up or down whilst keeping the mouse perfectly still. No event calls get registered.
4. Do the same and move the mouse this time - calls get registered.
5. Alternatively, you can use any mouse button to repeat steps described above - same result occurs.

Expected behavior: Scroll event should be called when using scroll wheel without moving the mouse
Actual behavior: You must move mouse in order to call the scroll event