OS: desktop

What steps will reproduce the problem?
(1)Select Advanced settings
(2)Expand Language settings
(3)Open Manage languages subpage

Things to notice:

When an item is checked in the lower list, an item is added to the upper list and the All languages list jumps down on the screen (because Enabled languages list has another element.

After a language is enabled, there are then two ways to uncheck the language (via the X in Enabled languages or by unchecking the language checkbox).

Problem:

The Manage languages UI behaves strangely.