Figured it out: The bug only happens with: org.gnome.mutter workspaces-only-on-primary true
which is only set in GNOME sessions because: /usr/share/glib-2.0/schemas/10_ubuntu-settings.gschema.override /usr/share/glib-2.0/schemas/00_org.gnome.shell.gschema.override You can avoid the bug by using the upstream default: org.gnome.mutter workspaces-only-on-primary false -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1976204 Title: Screen freeze and high CPU when a second monitor of different scaling factor is attached (but only if DING is active) To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1976204/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs