Or maybe it is depend on bug https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/179839 and keyboard locks when the shift key is held down for a 10 seconds.
Or maybe it is depend on bug https:/ /bugs.launchpad .net/ubuntu/ +source/ xorg-server/ +bug/179839 and keyboard locks when the shift key is held down for a 10 seconds.