Switch to laptop screen of external screen do nothing

Help
1

Hi. I recently switched to KDE. Before I had system with Xfce and before Windows. I don’t think my usecase is unusual. I have PC (not laptop) and 2 monitors. Main on the left, secondary on right. Before I was used to turn off secondary monitor after work. So I pressed Mod(Win)+P and chosen single monitor. Second one did went dark. All was ok.
When I switched to KDE I see similar stuff (it’s just named differently but I don’t care). When I press Mod+P and then choose Laptop screen, an icon that clearly shows only one monitor as output, screen just blinks and my desktop stays on both monitors. I have to manually go to display settings and disable secondary monitor. Same if I press switch to external screen. I still have output on both monitors like before without change.
It’s pretty annoying and I can’t seems to find any workaround so it will work as in Xfce or Windows before.
Why is it like this? Or how to fix it? Let me know what more info you want and how to obtain it.
Thank you.

2

Sounds like a bug, to be honest. But we’ll need more information to be sure.

Some questions:

  1. What version of Plasma are you using?
  2. What GPU do you have?
  3. What physical connectors are the monitors using, and what are they plugged into?
  4. Does the issue reproduce in both the X11 session as well as the Wayland session, or only one?
3

KDE Plasma Version: 5.27.9
KDE Frameworks Version: 5.112.0
Qt Version: 5.15.11
Kernel Version: 6.6.2-arch1-1 (64-bit)
Graphics Platform: X11
Graphics Processor: NVIDIA GeForce RTX 2070/PCIe/SSE2

Monitors are plugged into displayports (not hdmi) on RTX 2070.

I don’t know how to switch to Wayland. I don’t know if it’s possible for me on nvidia.

Edit: I must say I switched from XFCE, might be problem that something got left behind. I just don’t know what.

4

To log into a Wayland session, you choose “Plasma (Wayland)” from the session chooser menu in the bottom-left corner of the login screen. If you don’t see it there, that means your distro has split it out into its own package and you’ll have to find out what that package is and install it, then reboot.

Should generally work fine with NVIDIA.