1.8.9 stops accepting keyboard input

At random times (or at least, I have not discerned a pattern), the 1.8.9 Arduino (running on Mac OS 10.14.5 "Mojave") just stops accepting keyboard input. I can save using the File>Save menu item, but not by Cmd-S. No text I type is accepted. The visual GUI is responsive, but there is some problem in the keyboard handling. The only way to fix thisz is to use File>Save to save the file, quit Arduino, and restart it. This time-consuming, and very annoying, especially when it happens only a few keystrokes into the new session. Sometimes I can go for hours before it happens, sometimes less than a minute.

Has anyone reported this, is it being worked on, is there a beta fix?
joe