Windows 10 updates for Fall Creators Edition can cause monitor issues on some systems.
Windows 10 updates for Fall Creators Edition can cause monitor issues on some systems.
Essentially, launching CS:GO keeps everything smooth at 144Hz, but switching tabs causes the monitor to drop to 60Hz. When you return to the game, it restores the original settings, but closing the game leaves the monitor stuck at 60Hz unless you reboot your PC. You mentioned you've installed the drivers cleanly and updated via a full clean install.
I've received the update for a week already and it's just beginning now...