How to setup multiple monitor in KDE
For me, the easiest method to configure monitor under KDE is by installing KScreen from repo. Once installed, you can configure your monitor setting through Configure your Desktop)>>Hardware>>Display and Monitor> Display Configuration.
You may never need to configure it at all since a lot of time I’ve found KScreen smart enough to auto-configure my monitor. Still not sure why KDE developers don’t make KScreen as the default screen management software. In my opinion it’s much better than the default one.
Image credit: Techverse