When two docked windows are placed beside each other horizontally in the same dock area and you want to resize them the two resize handles work differently. When dragging the handle separating the docked windows, the proportions/ratio between the docked windows change, while dragging the handle close to the central widget area causes the complete area to resize and the docked windows to keep their proportion to each other as they grow or shrink in size.

The wanted result would be to resize the docked window and not the entire dock area when dragging the handle closest to the central widget.