I'm using plasma 5.8.7 under Ubuntu 16.04 (not an original Kubuntu installation), with several virtual desktops. I have also changed the panel options to "Only show tasks from the current desktop".
It seems that after every time I reboot, when I try to open an application, it appears on a random virtual desktop, rather on the one I'm working on.
Also, it doesn't update the panel correctly after the reboot, and some applications appear in the task manager on the wrong virtual desktop.
Has anyone noticed that? Is there any option to fix it?