someone else do this pls

For whatever reason, I can't alt+tab out of SC2. I tried googling the issue and many others have problems where their game freezes if they do, but I don't see anyone simply unable to alt tab. Nothing happens, it just stays in the game. I've tried switching the settings from Fullscreen to Windowed (Fullscreen) and it's the same in both. Has anyone bumped into a similar problem before and if so how did you fix it?

Theres a checkbox that disables alt tab in sc, could be this?