I have seen a few similar problems on SE. None of them match exactly, and unfortunately none of their solutions worked either.

The problem: Alt + Left key locks the screen. This is also the Chrome browser shortcut for back, so pretty frustrating.

Solutions tried: I've looked through all the keyboard shortcuts and nothing matches this particular combination. I can't see anything in Tweak Tools either.

When: most frustratingly, intermittently: when I first launch Chrome it doesn't happen. When I first start up my machine it doesn't happen. Something triggers this behaviour in my normal workflow, and then for the life of me I have no idea how to turn it off without restarting my system.

Set up: Ubuntu GNOME 16.04 on an Dell XPS 13

  • 1
    yeah, tumbleweed! Mar 27, 2017 at 12:45
  • I've got the same problem with a similar setup... Have you found a solution since you asked?
    – rixo
    Apr 19, 2017 at 21:03
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    The problem fixed itself. I still have no idea what caused it. Update and reboot is all I can recommend Apr 19, 2017 at 21:09
  • OK thanks. Reboot fixed it for me too. Unfortunately, I remember that I had already had the same problem in the past, so it comes back. Most probably some kind of bug in Gnome. I have a feeling that it has something to do about playing with my nvidia settings...
    – rixo
    Apr 20, 2017 at 21:41
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    If your problem/doubt is solved then accept answer, if not, comment on answer. :) Aug 1, 2018 at 18:05

1 Answer 1


This happened due to not restarting after upgrade.

I had similar problem but doesn't lock the screen rather it switches other screens in background, and it has labeled as tty1,tt2..., etc.

In my case there were 6 ttys opened and whenever I was doing alt + left arrow, it was switching to different ttys which are processes running in background and it also has login tty, kernel bootinfo tty, driver running tty.

It doesn't show only lock screen but when you switch again then you get your original chrome-screen back.

this may be the bug but after a restart, it works as we intended. hope this helps your answer.

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    I can't confirm whether this works or not as I have not experienced this problem in over a year, however I will accept if there are no other suggestions or objections Aug 3, 2018 at 9:10
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    @christopherlovell Just got here searching for a solution to this problem and can confirm that a simple reboot fixed it. What I can't work out is how I've had this problem for three days and hadn't yet tried turning it off and on again!
    – kevtufc
    Aug 3, 2018 at 9:21
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    I describe an easy solution here: askubuntu.com/a/1066803/452327
    – Juan Leni
    Aug 22, 2018 at 20:41
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    Confirmed that after rebooting after various upgrades, that the problem ("Alt+Left key locks the screen") went away. So this was "the" fix for me. Unfortunately, I did not notice what the system revision was at before the reboot, but afterwards it was "Ubuntu 18.04.1 LTS".
    – bgoodr
    Sep 9, 2018 at 15:07
  • It's been a few months, but I can confirm that this is still the solution for this, at least on 18.04
    – Asking
    Apr 19, 2019 at 15:21

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