I have a strange problem in Ubuntu 18.04 (I use a DELL Latitude E5550): sometimes when I type, some keys get "stuck", meaning that when I type "i", the result is an endless line of i-s ("iiiiiiiiiiiiii"). If backspace gets stuck, entire texts I wrote are deleted. I can stop this by pressing some other button.
I had the same problem in Ubuntu 16.04 while using the same laptop. I "solved" this issue by setting the keyboard to write only one character when I press down a button. However, this possibility seems to be missing from Ubuntu 18.04.
A few days ago I ran a hardware diagnostic, which found no problems on the hardware side.
uname -a
to your question? – Hee Jin Apr 29 '18 at 17:38