I see now, thanks. The lock screen in Unity7 is actually lightdm, not gdm. That's despite the fact that you logged in originally from gdm :)
** Package changed: gdm3 (Ubuntu) => lightdm (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1782101 Title: gdm nonfunctional on active screen switch Status in lightdm package in Ubuntu: New Bug description: I have double screen configuration (2 monitors). I face such issue: 1. I lock computer by pressing (Win+L) or it lock itself by timer 2. Mouse goes out of current monitor (password input field switches to second screen) 3. Upper buttons becomes nonfunctional such as language selection button, power indicator, volume control button, logging control button. It happens to both screens. 4. I cannot to unlock computer if language dosn't match language of password. The hard-reset is only option possible. I use Unity without switches to Gnome Shell. I tried to log gnome session (it's named Ubuntu) and I couldn't reproduce the issue. If lock computer I got completely different login page. There is no switch to the password input field if I move mouse pointer to the second screen. The password input field is fixed to the main screen. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: gdm3 3.28.2-0ubuntu1.3 ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18 Uname: Linux 4.15.0-23-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.2 Architecture: amd64 CurrentDesktop: Unity:Unity7:ubuntu Date: Tue Jul 17 11:57:02 2018 InstallationDate: Installed on 2017-04-03 (469 days ago) InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2) SourcePackage: gdm3 UpgradeStatus: Upgraded to bionic on 2018-05-03 (74 days ago) mtime.conffile..etc.gdm3.custom.conf: 2017-10-23T17:14:02.815788 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1782101/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp