The problem alerts stopped appearing on Thursday, April 29. SELinux
alerts discussed in a separate thread stopped at the same time. That
would have been when I did weekly patches ("dnf upgrade"). I also did
weekly patches on Thursday, May 06. Since the problems did not start
showing up again, I'm now confident they're really fixed.
So no bug has been submitted. I don't know what in the patches fixed
things, but this workstation is fixed.
I thank everyone who tried to help and/or give bug-writing tips. I've
marked this thread SOLVED. I will hunt down the SELinux alert thread to
close it too, if not already done.
Bill.