Package Pane - Right and left arrows require multiple key presses to scroll horizontally

[advice2020]

In the Package List pane, if the contents width goes beyond the right edge of window, a horizontal scrollbar is shown at bottom.
The LEFT/RIGHT ARROW keys are programmed to perform a horizontal scroll using your keyboard.
This does work, but appears to have strange behavior.
The LEFT/RIGHT ARROW keys have to be pressed multiple times in order to experience a horizontal scrolling action.
To me is seems like this horizontal scroll should be applied with the first pressing of the LEFT/RIGHT arrow.

Thank you to anyone who reads this