Incorrect alignment - MDI Application, TSpTBXDock with multi Toolbars

[sergSVK]

I discovered an unpleasant alignment of elements when switching between child windows. The bug is reproduced in the following sequence.

1. Open >1 child window
2. We reduce the width of any window until the rows of toolbars increase (by default, 1 non-fixed row)
3. Maximizing the child window
4. From the "Window" menu we switch between windows. When the window is resized at the top we see a bug. The child window area is visible in red (I made the child window color red). The height of the area is equal to the height of the toolbar.

I'm using Delphi 10.4 Sydney. I don't know if this bug can be reproduced on other versions. A test example is attached. The executable file is also attached.

Test.zip