I have three display connected to my laptop. One is the main (the laptop screen). When the logon comes it is displayed on all screens but only on one it seems to accept keypresses. The wrong one. How do I restrict the logon window to one screen only?
On my machines (which admittedly are using sway + sddm rather than KDE), each screen is independent - any one will work, but only the selected one will show keypresses as I’m typing. Is that what you mean? Or are you unable to select the others by moving the mouse across (or up, or down, but normally it would be across)?
It doesn’t look like SDDM has an option for only displaying on one screen, so if you need to restrict it to only one then you need to adjust the display configuration that its using.
Do the instructions in this post help? Login Screen Appearing On Multiple Displays - #8 by joesh-00