Every time I raise/lower the volume, or change screen brightness through the keyboard, the screen freezes for 1 to 2 seconds before the corresponding OSD appears and shows the change. It didn't happen on 16.04 - started on 18.04.

If I do the same command in the next couple seconds the freeze doesn't happen (the OSD is fast as it should be).

My computer is new (16G RAM, i7-8750H, nVIDIA GTX 1050ti). The problem happens exclusively on Gnome Shell + Xorg combination - if using cinnamon or Gnome Shell + Wayland it works as expected (but both options have their downsides too, so I prefer to stick with Gnome shell). Any ideas of why this is happening? It gets pretty annoying over time :(

Thank you!

3 Answers 3


The accepted answer to this other question of mine https://askubuntu.com/a/1163929/834984 also solved this problem.

Copied below the relevant part of the answer: "After some digging i found out the culprit is the ScrollLock key and that can be fixed by editing the layout file, which in my case is found at /usr/share/X11/xkb/symbols/br. The only modification i did was to remove or comment the line: modifier_map Mod3 { Scroll_Lock }; After that, set the language and layout back to Portugues (Brasil) and the problem was gone!"

Thank you Gustavo Silva

  • This problem still is up on ubuntu 20! I hope that canonical fix it, it makes an bad experience. Apr 25, 2020 at 11:40
  • I noticed that after some time, the problem is back. The modification i manually did was undone, doing it again fixed it. Do you know why it reversed back to original? May 1, 2020 at 19:56

Deleting the line

modifier_map Mod3 { Scroll_Lock }; 

at /usr/share/X11/xkb/symbols/br only worked for me after deleting the US keyboard input and adding it again, not just switching between them.

Now there still seems to be a delay, but it is very small and acceptable.


Just run the following command and it will fix:

sudo sed -i '/modifier_map Mod3   { Scroll_Lock }\;/ s/^\/*/\/\//' /usr/share/X11/xkb/symbols/br

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