Black screen for 1-2 seconds while alt-tabbing a fullscreen game or using a Windows key

When I Alt+Tab or use a Windows key to get out of a game (in this case World of Warcraft) and use a Windows feature or other program like Chrome, when I return to the game, I experience a 1-2 seconds black display.

This also happens when I use keyboard shortcuts to change volume and the Windows volume bar appear in game. I checked for graphics cards updates and also disabled Focus Assist in Windows, but the problem still persists.

I plugged my monitor to my motherboard and it looked fine anyway, but with changed settings in game.
I have 2x GTX 1070 Ti, and my monitor is LG 29" Wide Screen, and I run everything on Windows 10.

Do you have any idea or anyone have faced this problem ?

Solution 1:

This is normal for exclusive fullscreen games. It has to reinitialize DirectX and have it take over the display again. Try using Borderless Windowed instead of Fullscreen if the game supports it if you don't want to have this issue.

As for the volume overlay also causing the issue, John said below that either Windows or some program is trying to display something that is not the exclusive full-screen game.

Solution 2:

The other answer is incorrect. This used to be normal for exclusive fullscreen games. However, beginning with Windows 10 v1803 (March 2018), Microsoft introduced a feature called "Fullscreen Optimizations" that forces all games to use Borderless Windowed mode, even when the game requests exclusive fullscreen.

This feature is always on by default, but a number of things can cause it to stop working. These include:

• If you disabled Fullscreen Optimization for the game or disabled it system-wide, the slow alt+tab behavior will return. Many gamers do this intentionally because exclusive fullscreen has better performance.
• Focus Assist previously broke it. I believe this has been fixed in the latest version of Windows.
• Several version of NVidia drivers have been known to break it, so make sure to update your drivers.
• Certain version of Realtek drivers have been known to break it. I don't think those were ever fixed, so your only option may be to uninstall those and use the default Windows drivers.
• From this similar question, make sure GPU scaling is disabled and your refresh rate is set correctly in your GPU control panel.