Only in my PC with a n amd CPU and Neon (KDE 5.17.4) I have the right resolution on boot screen and in normal screen usage, but a bad resolution (too low) both in login screen and in screen lock screen.
I have searched on Google (they speak of a sddm.conf in /etc, but there isn't in Neon), but no valid solution.
Any help?
Thank you

You can try this System Settings > Startup and Shutdown > Login Screen (SDDM) > Advanced tab > Click the Sync button. That will make SDDM the same resolution, etc. as the desktop.

kde-mikedee wrote:You can try this System Settings > Startup and Shutdown > Login Screen (SDDM) > Advanced tab > Click the Sync button. That will make SDDM the same resolution, etc. as the desktop.

Thank you. However it seems not work (maybe it is due to the fact that I have changed something in sddm theme...)