I should add that, in researching old posts on these issues, I gather that nVidia driver(s) have been a factor; so note that the last Ubuntu Updater package prior to all this did also include an update to the nVidia driver package.
I should add that, in researching old posts on these issues, I gather that nVidia driver(s) have been a factor; so note that the last Ubuntu Updater package prior to all this did also include an update to the nVidia driver package.