Unexpected scroll down within editor

Using ver. 2.2.0, WP 4.9.8

I find now an unexpected behavior in the editor, that is to say, the right panel of the screen on the backend.
Suppose there is a text editor widget containing text that is longer than the view port. I go to the end of that widget and click after the last character, with the intention of adding more text. But, unexpectedly, the text scrolls up, such that the top of the text editor widget is positioned in the middle of the viewport. Consequently, the bottom of the widget, where I want to work, is off the screen.
I note this behavior whether the navigator is displayed or not.

On the other hand, when I click in the left panel at the end of such a text editor widget, to add more text, it would be nice if the right panel scrolls down to the same position so I see the effects of my editing in the left panel shown directly in the right panel. This does not happen.