From this similar question, make sure GPU scaling is disabled and your refresh rate is set correctly in your GPU control panel.I don't think those were ever fixed, so your only option may be to uninstall those and use the default Windows drivers. Certain version of Realtek drivers have been known to break it.Several version of NVidia drivers have been known to break it, so make sure to update your drivers.I believe this has been fixed in the latest version of Windows. Many gamers do this intentionally because exclusive fullscreen has better performance. If you disabled Fullscreen Optimization for the game or disabled it system-wide, the slow alt+tab behavior will return.This feature is always on by default, but a number of things can cause it to stop working. If you can run two monitors you can use wow in windowed mode and not need to. 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. I run Warcraft in full screen windowed mode and have wowhead open in a.
This used to be normal for exclusive fullscreen games.
