It sounds like you might have a key repeating, only logically in software, and only in gdm3.
You may wish to: (a) Test a different keyboard, even briefly; or (b) When the problem happens again, on the login screen tap your Enter, Shift, Ctrl, Alt keys a few times each. If one is virtually stuck down in software that might unstick it. ** Changed in: gdm3 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm3 in Ubuntu. https://bugs.launchpad.net/bugs/1741511 Title: GDM3 display manager: logon constantly trying to "press enter" - unable to login using PTY To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1741511/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs