I once had trouble getting full native resolution on an external 2560x1080 monitor. It turned out to be a problem with the DisplayPort -> HDMI monitor cable I had (not enough bandwidth without using a custom reduced frequency mode via xrandr/way harded custom EDID hacks for wayland), and switching to a better cable (DP -> DP, rated for 4K video) allowed me full use of the monitor.
Have you ruled out hardware/cable problems by, e.g. booting to a different OS, or trying a different cable? -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1895301 Title: XrandR does not propose 3440x1440 21:9 resolution To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1895301/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp