The SELinux alerts stopped on Thursday April 29. That would have been when I did weekly patches ("dnf upgrade"). I also did weekly patches on Thursday, May 06. Since the alerts did not start showing up again, I'm now confident they're really fixed.
I've added a comment to "https://bugzilla.redhat.com/show_bug.cgi?id=1951668" saying what I said in the preceding paragraph of this post.
I don't know what in the patches fixed things, but this workstation is fixed.
I thank everyone who tried help. I've marked this thread SOLVED.
Bill.