Kubuntu Forums - Kubuntu Catchall https://www.kubuntuforums.net/ en Mon, 27 Jul 2026 21:54:24 GMT vBulletin 60 images/misc/rss.png Kubuntu Forums - Kubuntu Catchall https://www.kubuntuforums.net/ Kubuntu 26.04: Black screen after screen lock or display power off (Wayland, NVIDIA RTX 3070) https://www.kubuntuforums.net/forum/general/kubuntu-catchall/693330-kubuntu-26-04-black-screen-after-screen-lock-or-display-power-off-wayland-nvidia-rtx-3070 Wed, 15 Jul 2026 22:37:11 GMT I upgraded from Kubuntu 25.10 to Kubuntu 26.04 LTS. Since the upgrade, my graphical session becomes unusable whenever the screen locks or the display...
System
  • Kubuntu 26.04 LTS
  • KDE Plasma 6.6.5
  • Wayland session
  • Linux kernel 7.0.0-27-generic
  • NVIDIA GeForce RTX 3070
  • NVIDIA driver 580.159.03
Problem
The issue occurs in at least these situations:
  • The screen locks (loginctl lock-session)
  • The display powers off after inactivity
  • Suspend also appears to trigger the same behavior
Steps to reproduce
  1. Log into a Plasma Wayland session.
  2. Run:
    loginctl lock-session

    (or wait for the screen to lock/power off automatically.)
  3. Attempt to wake the session.
Expected behavior
The lock screen should appear and the session should be usable after entering the password.

Actual behavior
  • The monitor wakes up to a black screen.
  • The mouse cursor is visible and can be moved.
  • Typing the password does not restore the session.
  • Ctrl+Alt+F2 (or another TTY) still works.
  • The system itself appears to remain running.
Additional observations
From a TTY, I tried:
systemctl --user restart plasma-kwin_wayland.service

This changed the display to what looked like the graphical login screen. The clock updated, the mouse worked, and I could type my password. However, pressing Enter caused the graphical interface to freeze completely.

From another TTY I then tried:
systemctl restart sddm

After this, the screen became black with only a white cursor/underscore in the upper-left corner, and even switching to another TTY no longer worked. I had to power-cycle the machine.]]> Kubuntu Catchall Yamanqui https://www.kubuntuforums.net/forum/general/kubuntu-catchall/693330-kubuntu-26-04-black-screen-after-screen-lock-or-display-power-off-wayland-nvidia-rtx-3070