Docked windows size problem

Hi, I have two windows. One is docked North, and one is docked South.
But south docked window is eating some north docked window space, I tried several possibilities, but couldn’t figure out how to resolve this situation.

Here is how north window look like:

And here is the result, south window goes over some north window space:

Did you get it fixed? What was the solution? Was the window not really docked correctly?