I found a way to reproduce it. It happens when the mouse pointer jumps
between the two displayport monitors. If I keep moving the mouse between
the two monitors it happens each couple of seconds.
If I disable the vga monitor. The problem is gone...
I have no idea of what is happening but at least
I have the same problem happening after the upgrade from 15.10 to 16.04.
I have a Dell Latitude E7450 plugged into a dock with 3 external
monitors (I'm not using the notebook display). After the upgrade by some
reason two of the monitors randomly blanks and come back after 1 or 2
seconds. I couldn
