https://bugs.winehq.org/show_bug.cgi?id=50232
--- Comment #5 from Zebediah Figura z.figura12@gmail.com --- It's a bit of an odd case. The application creates one visible window ("SimpleGraphic Console") on a separate thread, then creates another visible window ("SimpleGraphic") on the main thread, then hides it.
On Windows, after the second window is created, it is active but the first is still foreground. On Wine, the second is foreground. On Windows, the second window doesn't actually become deactivated as a result of SW_HIDE, apparently because it's not foreground; I'm not sure whether Wine correctly accounts for this, but it's a moot point since the window isn't foreground anyway.
Focus is my least favourite part of user32. I could probably write a hack if necessary, but I am rather disinterested in fixing this bug upstream personally.