I'm not sure you can turn it off. What I have noticed though, is that if you gently put the window at the top, it'll hang there for long enough for Magnet to snap the window, but if you throw it at the bar it'll activate Mission Control.
Or more to the point, if you put the window at the top of the screen, then push up a bit more, that's when Mission Control activates.
That's frustrating. I also noticed that on this version of Mac OS, with After Effects at least, Magnet control of the window seems not to work. Using the ctrl + enter command does nothing and gently dragging to nearly the top of the screen doesn't do anything either. Seems to work fine with other apps like web browsers and Finder though.
I used macs for like 15 years before I realized I could double click the top bar of a window to maximize but not full screen it.
Also, try rectangle! Wonderful window tiling and it’s open source. I wouldn’t use a Mac without it
You can disable Mission Control and Spaces by typing the following command in terminal:
defaults write com.apple.dock mcx-expose-disabled -bool TRUE && killall Dock
If for some reason you want it back you can type in the following into terminal:
defaults delete com.apple.dock mcx-expose-disabled && killall Dock
You can google the commands above to check the authenticity of my answer. Hope this helps. 😊
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