I am having the same issue described here: https://discussions.apple.com/thread/8296956 and here: https://discussions.apple.com/thread/8515674. Neither have an answer. This issue is driving me insane and meaning I can't easily switch windows on my new macbook pro. Only way to temporarily fix it is to restart. This only lasts a short time before the issue happens again.
MacBook Pro with Touch Bar
Unfortunately safe mode wasn't particularly useful because it already went away when ever I restarted.
Here is how I have resolved the issue: I closed apps one at a time to test if the issue kept happening. Then when it stopped I re-opened the last app to see what was causing it. It ended up being a problem with Steam, specifically the game Two Point Hospital.
To fix the issue, I went into System Preferences > Mission Control. I had to deselect the option "Displays have seperate spaces". This stops the app opening in a new space when it goes into full screen mode.
Still very annoying, but glad I have found a fix.
Hi magmar2k,
Thanks for coming to Apple Support Communities for help with Mission Control shrinking windows.
For reference, here is an article on Mission Control: Use Mission Control on your Mac. Have you tried going into System Preferences > Mission Control and selecting or deselecting some of the options and testing the issue further?
I took a look at the previous threads and it seems safe mode helped resolve it in the second thread. This isolated the issue as being caused by third-party software. Did you try either safe boot or new user account? Here's how: Use safe mode to isolate issues with your Mac and How to test an issue in another user account on your Mac.
Let me know how that goes.
Have a fantastic day!
mission control shrinks windows to nothing
