Selecting a menu option will have the child window open behind Krita. For example, in main menu, select "Settings" then "Configure Krita". The "configure krita" appears then the main Krita program window moves in front of the "configure.." window. While the child window is showing in Windows tool bar, sometimes I can't get the child window to move in front of the main window by selecting it. I'm running Krita 4.0.0 on a Windows 10 Pro 64-bit system with NVDIA graphics.
Is it doing it every time. I am playing with a nightly build on my Windows 10 machine and the child windows seem to be going in front. Did it always work this way for you?
Today I updated to version 4.0.1 and have not had the child window issue so far. Perhaps this latest version fixed it?
That is very possible. I think there was a child window update that did happen in the 4.0.1 bug fix release. I am closing this for now and marking it as resolved. thanks for the bug report.