I’ve hooked up a 3440×1440 display to my Ubuntu laptop.
The laptop detected and used the screen with a lower default resolution of 2560×1440, and no higher option available in display settings.
I’ve used the following commands to add the custom resolution:
sudo xrandr --newmode "3440x1440_60.00" 419.50 3440 3696 4064 4688 1440 1443 1453 1493 -hsync +vsync sudo xrandr --addmode HDMI-2 "3440x1440_60.00"
and it does indeed add the setting to the settings screen. But when I try to apply it, it instantly switches back to 2560×1440.
This display is correctly autodetected and used at full resolution by another computer (non-Ubuntu).
I have checked that my grub conf does not contain
I have also checked that my GPU supports higher resolutions.
How can I troubleshoot this issue?