For the record, this just happened to me on a *fresh* install of Ubuntu 18.04.
The first thing I did after system installed months ago was to install Unity from repositories (and set lightdm as the default greeter). Unity may not be the default anymore in 18.04 but it runs and looks great. Today I needed to test Gnome Shell. So I logged out, and in the greeter selected "Ubuntu (default)" instead of pre-selected "Ubuntu (Unity)". And that *insane* zoom up happened. Same as described by OP. Logging out and back into Unity everything is OK. Also tried "Ubuntu (default on Wayland)" and same super zoom -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1705156 Title: gnome-shell interface shows up extremely scaled up To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1705156/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs