That's odd because 3440x1440 actually has lower bandwidth requirements (fewer pixels) than 3840x2160. Still, to go above 60Hz you will need both your HDMI cable and your graphics card to be capable of HDMI 2.1, not just 2.0.
Please tell us the model of graphics card you are using. If you're just using the integrated graphics of the Intel i7--1255U chip then I'm not sure that can do it with HDMI. DisplayPort looks more certain to work (you may need a USB-C to DisplayPort cable for that). Please also run this so we can see the modes that the kernel driver believes are possible: sudo apt install drm-info drm_info > drminfo.txt and attach the resulting text file here. ** Changed in: mutter (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/2046798 Title: Ubuntu Wayland does not support 21:9 monitor Status in mutter package in Ubuntu: Incomplete Bug description: My second monitor attached to HDMI of my Lenovo V15 is DELL S3422DWG and has aspect 21:9 with resolution 3440x1440, with supported resfresh at 100Hz. I could not set native resolution on my second HDMI DELL S3422DWG in any way. I tried cvt, modeset, passing boot parameters to grub, porting EDID from Windows 10 to custom EDID with grub parameters. Every one move ended up with 4k resolution 3840x2160(16:9). And I saw a lot of similar reports on unresolved 21:9 issue on reddit, stackoverflow etc. Kind regards. --- ProblemType: Bug ApportVersion: 2.27.0-0ubuntu5 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 23.10 InstallationDate: Installed on 2023-11-01 (49 days ago) InstallationMedia: Ubuntu 23.10.1 "Mantic Minotaur" - Release amd64 (20231016.1) Package: mutter 45.2-0ubuntu1 PackageArchitecture: amd64 ProcEnviron: LANG=ru_RU.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcVersionSignature: Ubuntu 6.5.0-14.14-generic 6.5.3 Tags: mantic wayland-session Uname: Linux 6.5.0-14-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sudo users _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2046798/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp