OSX Catalina 10.15; Illustrator 24.0.1 with Creative Cloud 5.0.0.354
Safari, Mail, and Notes open in background

Sometimes after using CMD+SHIFT+S to open Save As dialog, the dialog box will not be focused; filename will not be highlighted; TAB will not cycle through input fields; ESC will not close dialog box. Clicking somewhere on the box is the only way I've found to make it responsive as normal. After doing so, I can close the dialog with ESC; re-entering the keyboard shortcut afterwards tends to result in expected behavior, but sometimes the problem repeats. The keyboard shortcut should immediately open the dialog and focus the filename.
I haven't been able to reliably reproduce the problem. It's happened with several filetypes, all saved to the user folder on the system drive, with and without other apps open, with files that were heavily edited and files whose only change was to the filename. When saving multiple files one after the other, without going to a different app, some may have the problem and others may not.