Describe the bug
The mouse wheel asuage of up/down keys is buggy in the knowledge base.

If you use it in the left text list, it jumps all the way to the top or buttom.

If you use it in the right text list, only the right list will react.

If you push the up or down keys, only the left list will change. It's not possible to change the entry in the right list.

To Reproduce
Steps to reproduce the behavior:

1. Use the mouse wheel on the left or right text list and see what happens

Expected behavior

• When mousewheel used on left list: Scroll by one entry
• When mousewheel is used on right list: Scroll right list
• There's some way to change the right list entry with keys

Desktop:

• OS: GNU/Linux
• Python version: 3.8.1
• Version: 00b8d20