Gracias por el aporte, pero sigue sin poder verse correctamente. No entiendo por qué en otras distribuciones con el mismo escritorio no ocurre esto Y en slimbookOS si. Entiendo que se debería de adaptar.

Hola,

If you’re referring to the SDDM greeter, the one that shows only at boot and not on the lock screen, this Reddit post might help:

https://www.reddit.com/r/kde/comments/1bahvog/fix_sddm_on_hidpi_screens_on_plasma_6/

Here’s the solution provided by user kalzEOS:

1. Create a text file (if it doesn’t already exist) at

 /etc/sddm.conf.d/hidpi.conf 

2. Add the following content:

[Wayland]
EnableHiDPI=true
[X11]
EnableHiDPI=true
[General]
GreeterEnvironment=QT_SCREEN_SCALE_FACTORS=2, QT_FONT_DPI=192

Adjust QT_SCREEN_SCALE_FACTORS=2 to the value you prefer.

3. Since you have multiple monitors, you can set a different scaling factor for each one, separated by a semicolon. The last line becomes:

GreeterEnvironment=QT_SCREEN_SCALE_FACTORS=1.5;1, QT_FONT_DPI=192

This is the configuration I am using on my Slimbook Evo 14, where "1.5" is for the laptop display and "1" for the external full HD monitor.

Hola, ya está hecho y no hay cambios, Sigue igual.

You can try also this:
System settings > colors & themes > login screen (sddm) > click on "Apply Plasma Settings" on top right

No cambia, y he editado el archivo /etc/ssdm.conf y tampoco. no sé por qué no respeta la resolución del monitor si con otras distros con plasma no tengo este problema.

Thanks for the contribution, I will look into how to change the system resolution.

you can install the grub-customizer tool on Slimbook OS and change the resolution to the boot screen

sudo add-apt-repository ppa:danielrichter2007/grub-customizer

sudo apt update && sudo apt install grub-customizer

If the issue is related to the login screen of Plasma desktop (sddm), you can edit the resolution in the system settings