Hello,
I am new to KDE. I see it has great dual monitor support.
I often plug and unplug a second monitor to my laptop. If I have made some panels on the second monitor and then unplug it, they will go to the other monitor(and the other monito's panels dissappear).Then when I plug it back in, all of the panels from all of the two monitors are crammed in the monitor that wasn't unplugged(the laptop monitor). Is there a way to say to KDE that the configuration should be saved for when the monitor is plugged back in?
As dynamic plugging/unplugging isn't that rare I was surprised not to find other threads about it. Maybe it is something in the settings that I've missed.

Have you tried to change your primary monitor?

In System Settings -> Display and monitor -> Primary output is set to my laptop's monitor. Is this what you are talking about?