After using my Mac for a while, I notice that some of the desktop space thumbnails blur and hide their window thumbnails in Mission Control. See the screenshot below for an example.
The only way I have found to resume showing all window thumbnails on all desktops is to log out and log back in. Closing the blurred desktop makes the next desktop blur instead.
I am using macOS High Sierra. I think I've observed the same behavior on Sierra, and I don't recall seeing it on macOS versions before Sierra.
What might be causing this?
I suspect the cause might be something that one or more video conference or screen sharing applications does, but I haven't been able to isolate which one or under what conditions. I think I have observed the symptoms after using multiple different applications, possibly including Google Hangouts, Hangouts Meet, Zoom, and GoToMeeting.
What might prevent it from happening?
