Bug 498424

SUMMARY
After playing a game (mostly with Proton (Wine), so both Steam and the game are run under XWayland), sometimes Steam gets the focus without raising the window. I also usually have Firefox (Wayland, IIRC) open.

What it happens is that, after exiting the game, I see the Firefox window on top but on the taskbar Steam is active.
When I click inside the Firefox window, Steam gets the input instead.
To fix this, I have to force the Steam's window to be visible and then switch back to Firefox (or other windows). Then everything resumes to work fine.

STEPS TO REPRODUCE
1. Open Steam
2. Launch a game (preferably a game running via Proton, such that it uses XWayland. IDK if it's required, though)
3. Open Firefox (or other apps, I mostly have Firefox open so...)
4. Alt-Tab between the game and Firefox (imagine I'm searching a wiki of the game for items' descriptions)
5. Exit the game
6. Firefox should be the visible window; try to interact with it

OBSERVED RESULT
Sometimes, Steam receives the focus but the window isn't visibile because it's covered by Firefox.
Yet, KWin thinks somehow that the input events should be sent to Steam, instead to Firefox.
To restore the correct behavior, switch to Steam and then switch back to Firefox.

EXPECTED RESULT
If Steam gets the focus, KWin should work correctly.
Otherwise, Steam shouldn't get the focus and the last active window (Firefox) should get it, instead.
In any case, the behavior MUST be coherent between focused window and visible window.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: ArchLinux, Plasma/kwin 6.2.5, Wayland
KDE Plasma Version: 6.2.5
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1

ADDITIONAL INFORMATION