I've been using 2 screens (laptop + external) for some time.
It's worked OK for some time, but recently (some update?) it's working less
well.
After using just the laptop, I connect the monitor. In the past, kde
doesn't notice and I need to run xrandr to turn on the monitor. Now, it
seems to turn on monitor (after a bit of delay), but the laptop screen then
has no background (just black), and right click on laptop background does
nothing. Running xrandr doesn't fix it. Only logoff/logon fixes it.