I can confirm this as well when using Ubuntu 17.10. I'm on a desktop (Shuttle XPC DH110SE) with Skylake processor and Intel graphics with latest updates.
Didn't have any problems on 17.04, don't have problems when using Gnome on logon. What I can add: I have no extension enabled - at least none of the ones displayed in Gnome Tweaks' "Extensions" tab. And it seemed to force log-off when a HDMI cable was plugged into my PC, but was not connected to a display. The actual connection to the display is done via DisplayPort. So the dead-end HDMI cable could cause trouble? -- 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/1721428 Title: Artful (17.10) Session logout after screen turned off To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/1721428/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs