It happened immediately after I inadvertently touched the edge of my touch-screen while adjusting the angle of my laptop screen. (See my similar statement in Comment #9).
Usually, I carefully avoid using my touch screen, because that triggers this problem.
(Note I use Dash-to-Dock extension, in case that has anything to do with this bug? Is anyone else using Dash-to-Dock or Dash-to-Panel?)
I experienced this bug just yesterday on 18.04...
It happened immediately after I inadvertently touched the edge of my touch-screen while adjusting the angle of my laptop screen. (See my similar statement in Comment #9).
Usually, I carefully avoid using my touch screen, because that triggers this problem.
(Note I use Dash-to-Dock extension, in case that has anything to do with this bug? Is anyone else using Dash-to-Dock or Dash-to-Panel?)