Gregkonji
Why does it happen? What you posted looks like unwanted behavior to me.
tenfoot
Why does it happen icontakt? Can't for the life of me imagine why this behaviour is intended.
I too thought it was a bug when I first encountered it, and took quite a while to realize it wasn't. As you can see in the image below, it's because of the "Track view" option under "Control Strips Visible in". If you use a control surface, you know what these options are for.
As for the issue you both are having, I'm guessing it's because you don't have the Console view loaded in the screen. A forum member (SquireBum) discovered about the same time last year that the issue occurs if you don't have the Console view loaded. It's better to load it, dock it in the MultiDock and collapse it. You can always expand the MultiDock by hitting D.