How to turn off window focus when working with windowed mode?

dont know where to report or tell about and how to solve super annoying stuff in Krita (latest)
i work with two files in window mode
and if i change brush whyle iam in window mode
every time i try to start paint, window gets selected with light blue, then i must pres brush against canvas one more time to get rid of it.

Using the 4.2.9 Linux appimage, I don’t get this happening if I select a new brush preset and paint in the same subwindow.
I only have to click on the workspace to activate it if I move to another subwindow.

Which operating system are you using?
Is this the case for you with the mouse and with a drawing tablet?

win 10
wacom intuos M

Do you mean you want the first click to start painting directly?

I have two windows tiled side by side, if I want to paint in one i have to first select the window and then paint on the canvas, the first click itself is not going to paint. This is a sensible design, the window is not active so the brush doesn’t paint in it directly.

P.S. I also edited your title to reflect the question properly.

ye. i would prefer to paint with first click.
also, when i work only in one window, brush thinks i need to select same window agen

I’ve just tried it with Windows 10 running the 4.2.9 portable .zip package and one image open in a subwindow. (I use a Wacom Intuos Draw.)
If I select a new brush preset from the Brush Presets docker then I can paint on the image immediately.
The subwindow title bar stays dark blue at all times.
If I have another application open and active (but not covering the screen) then I can immediately paint on the image in the subwindow as soon as I touch it with the cursor because it becomes active as soon as I touch it.
All this with mouse or stylus.
I can’t think of any Windows system level setting/configuration that might cause the behaviour you describe.