Hardware: Librem 13 v2
Software: PureOS 8.0 with the latest kernel and updates
Desktop: Default Gnome with Wayland (also tested with Gnome + X11)
Problem: When I connect an external 4k monitor over HDMI, the GUI display configuration tool maxes out at 1920x1080--the same resolution as my laptop display. This would make sense if I were mirroring displays but in this case I'm selecting "Join Displays".
I also logged out and tried this with Gnome and X11 with the same result. When using X11, xrandr will not show any monitor modes higher than 1920x1080 for the HDMI display.
- Connect external display with a native resolution greater than 1920x1080.
- Launch Gnome Display configuration tool.
- Select Join Displays.
- Select the connected monitor instead of "Built-in Display"
- Note the available resolutions in the "Resolution" drop-down menu. You should see no resolutions higher than 1920x1080.