Multiple scrollbars throughout the editor bounce back when the user scrolls with the mouse wheel.
The effect looks like the scrollbar is rubber banding when scrolled.
This issue has been found with the following scrollbars:
REGRESSION: Yes
Worked: 4.12.5 Binary CL-3039270
Broken: 4.13 Binary CL-3078722
1. Open UE4Editor.exe
2. Open any project
3. Select Edit > Project Settings
4. Scroll the left side of the Project Settings window using the Mouse Wheel
RESULT:
The scrollbar bounces back when scrolled with the mouse wheel.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-34345 in the post.