To stretch or not to stretch

In the controller event editor, the stretch doesn’t stretch at all. It compresses, but it doesn’t stretch. Say you have this:

You select it all, then it shows this:

I can’t show the screenshot of the handle for stretch because when I press Cmd as part of the shortcut for screenshots, it changes the pointer. But you know where the stretch handle is, at the bottom left and bottom right corners of the selected area.

Well, if I grab the handle on the right and I want to stretch the selection, so I click it and drag it to the right, it doesn’t go anywhere. Likewise, if I click and drag the one on the left and move it to the left, it doesn’t stretch anything.

But I can compress just fine in both directions:

So what am I missing here?

I think the tool is designed to only stretch/compress within the boundaries of the selection.
A workaround for stretching is to make a create a new event on the CC lane at the position where you want to stretch to. This way you can expand the selection to inlcude this new point and stretch until there.