Fullscreen games minimize to tiny screen after Alt-Tab (Steam, Heroes VI)

Hi everyone,

I’m having an issue with fullscreen games on Zorin OS.

When I run a game from Steam in fullscreen mode (not windowed), everything works fine. However, if I switch to another application (e.g., Alt+Tab) and then return to the game, the display breaks:

  • The screen becomes mostly black
  • The game appears as a very small window in the top-left corner
  • I can’t restore it to normal fullscreen

The only workaround is to force close the game and also the Ubisoft launcher (I believe it’s Ubisoft Connect).

Game: Heroes of Might and Magic VI (probably others as well)

What I’ve tried:

  • Running in windowed mode (works, but I prefer fullscreen - it has an ugly blue Windows bar on top)
  • Tried to run with borderless window but launch settings in Steam are not working
  • Restarting the game

System info:

  • Zorin OS version: 18 Core
  • Desktop environment: (GNOME/Xfce, if known)
  • GPU: NVIDIA 4060Ti
  • Drivers: proprietary (as advised by Zorin)
  • Proton version in Steam: Proton Experimental

Has anyone encountered this issue or knows a fix? Could it be related to Proton, display scaling, or fullscreen handling?

Thanks!

Welcome to the Forum!

Is Steam installed as Flatpak or .deb/APT Version? Does Your System run in Wayland or X11? What Nvidia Driver do you use? You can check that with the Terminal Command echo $XDG_SESSION_TYPE

1 Like

This is known to happen on Flatpak Steam when using alt+tab, so I agree that fully removing it and instead using

sudo apt install steam

is the smart first step.