Please: 1. Try selecting 'Ubuntu on Wayland' from the login screen and tell us if that has the same bug.
2. Tell us if you are using any fractional scaling settings. 3. Mutter/gnome-shell remembers multiple different display configurations. So it sounds like it's just switching configurations when you close the laptop screen (which it might see as disconnected or turned off). If you want that configuration to use 2560 ⨉ 1440 then you may need to set that resolution _while_ the laptop lid is closed. I hope that fixes the issue... ** Tags added: multimonitor ** 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/1888800 Title: Resolution of external monitor goes back to its default resolution when laptop lid is closed Status in mutter package in Ubuntu: Incomplete Bug description: The default resolution of my external monitor is 4K UHD (3840 ⨉ 2160). I set its resolution to a lower value (2560 ⨉ 1440). The external monitor is attached to a laptop. When I close the laptop lid, the built-in display is turned off, which is desired, however, the external monitor goes back to its default resolution (3840 ⨉ 2160), which is not desired. When I open back the lid, the built-in display is turned on, and the external monitor resolution stays with the default value (3840 ⨉ 2160), which is also not desired. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: mutter 3.36.3-0ubuntu0.20.04.1 ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44 Uname: Linux 5.4.0-42-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.4 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Fri Jul 24 08:56:58 2020 InstallationDate: Installed on 2020-04-26 (88 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: mutter UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1888800/+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