Ok, so, I've tried it on another computer, also a Mac, same version of AC, all the same settings for OSX and AC.
This is what I've realized: it happens with files that are big enough to take some processing time for certain commands; when AC is in mid-command-processing—even if the little watch-cursor doesn't come up because the particular process is quick—if I press ESC, the AC window will exit full screen.
I can press ESC multiple times when AC is not processing anything at all, and ESC will not cause exit full screen. I can also press esc with a tool selected, a marquee selection and object selected, and after three ESC presses, AC will not exit full screen.
This all being said, I really hope there is a way to stop AC from existing full screen when I press ESC under any circumstance, even if AC is in mid command-processing.
Any thoughts?
TV / Film Production: Sr. Set Designer
Art Directors Guild, Local 800
Archicad Latest Version
MacBook Pro (15-inch, 2018), 2.9 GHz Intel Core i9, >32 GB 2400 MHz DDR4, Radeon Pro Vega 20 4080 MB, Intel UHD Graphics 630 1536 MB