Docking Windows align problem with Manipulation panel

When the Manipulation window is a single window then the content aligns dependand of dimension and position. When it is at the ground of the window then it appears horizontal aligned. When i resize it and put it at let`s say the left side then the items gets sorted underneath.

I found a way to break this pattern. You can dock panels together to be tabbed. And this breaks the horizontal alignmend of the Manipulation window. Interesting behaviour