Refresh Rate and Display Issues with Lock Screen and Application Launcher Respectively


I am having two main issues with KDE (on Fedora 40, minimal install):

  1. When opening the application launcher it sometimes appears behind the taskbar, this behaviour is inconsistent and the launcher appears at varying ‘depths’ behind the taskbar until I hover over an icon. This issue appears to only occur on one specific user account.

    (Image with power off, restart buttons etc. behind the taskbar)

  2. When clicking on switch user only one user (the current user) appears on the lock screen, then the screen turns momentarily black and when it is on again the refresh rate defaults back to 60hz from its original refresh rate, but the other users are now visible, when switching to another user the monitor turns black again and adjusts itself to the user’s refresh rate.

Is there any way to remedy these two issues? Perhaps there is a system-wide setting I can apply for a permanent default refresh rate that applies to the lock screen / everywhere else in the system including new user accounts that hopefully preserves VRR?

Any help would be appreciated.

The second one is normal behavior: when you switch user, first the lock screen gets engaged - which is the “only one user lock screen”, then the screen switches to the virtual terminal with the SDDM login manager - the SDDM login manager uses default (“safe”) display settings, then when you log in you get another VT switch and the new user has their own display settings.

With SDDM in Wayland mode (which may or may not be the default - check if /etc/sddm.conf has DisplayServer=wayland), you can have one user apply their display configuration to the SDDM managed screen, by going to System Settings → Colors & Themes → Login Screen (SDDM) and clicking Apply Plasma Settings… this should cause SDDM to use the refresh rate set by that user - but you’d still get the blanking behavior as that happens as part of the VT switch.

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Thanks for your help.

That indeed has applied my native refresh rate to the lock screen and a resintall of Fedora has fixed the first issue in case anyone runs into it (although I am still unsure about its cause).

There was an issue where some menus (notably the klipper mouse position menu) was shown behind “always on top” elements, and that was fixed. The main menu issue might be related.