An hour ago Wordfence upgraded to its latest version 6.1.4 and the results on my site were catatrosphical.
Error Rate jumped from 0% to 97%+ (the error is Duplicate column name 'permanent') and transaction times doubled.
http://prntscr.com/auy457
I first tried to delete caches - did not work. Then I tried to simply disable wordfence: did not work either. The errors were still there.
I then tried to delete (errors stopped) and then reinstall a fresh version: did not work, the errors re-appeared.
So I had to delete and use wordfence assitant to completely delete all the tables, and then reinstall a fresh version and re-import the settings, as I described in my post 6 days ago.
I have now disabled automatic upgrades, but am not sure it's worth my time keeping this plugin which causes so much work with each upgrade.