STEPS TO REPRODUCE 1. Laptop with discrete Nvidia 1050Ti 2. Installed optimus-manager 3. Log in on built in monitor 4. Connect external monitor OBSERVED RESULT Desktop unresponsive EXPECTED RESULT Desktop work normally. No need for additional actions. SOFTWARE/OS VERSIONS Linux: 6.13.8-arch1-1 (64-bit) KDE Plasma Version: 6.3.3 KDE Frameworks Version: 6.12.0 Qt Version: 6.8.2 ADDITIONAL INFORMATION Every time I want to connect external monitor I need to press Ctrl+Alt+Backspace (restart X server I guess) because after connecting external monitor desktop is unresponsive. Same issue on X11 and Wayland. I use optimus-manager because I need to force Nvidia card as my main GPU for desktop rendering. My integrated Intel® UHD Graphics 630 is too weak for desktop rendering. It struggles to have 60 FPS on external monitor. But on built in monitor everyting works fine. I noticed this bug after updating to Plasma 6.
Can you get a backtrace of what plasmashell is doing when it's hung? You'll need to run this either from TTY or ssh'd into the system, since the desktop freezes. Run gdb attach -p $(pidof plasmashell) in a terminal while it's hung If it says "--Type for more, q to quit, c to continue without paging--" at the bottom of the terminal window, press the "c" key. When you see a prompt that says "(gdb)", type "bt" and press the enter key. If it says "--Type for more, q to quit, c to continue without paging--" at the bottom of the terminal window, press the "c" key. Copy-and-paste the contents of the terminal window into a comment here. Thanks!
Possibly related, another bug where the screen freezes for ~10 seconds, also on a system using Optimus https://bugs.kde.org/show_bug.cgi?id=488603