16.04 - Delay on screen lock until I move mouse - Ask Ubuntu

i have had problem ubuntu 16.04 workstation screen lock several months. when lock it, of time, walk away , come after time when should locked see screen showing left on screen. click mouse or keyboard goes lock screen , have enter password before using it. however, when away displaying contents of screen. concerns me.

is configuration error, bug or need investigate problem?

ok, until bug fixed, made quick , dirty script wiggles mouse 1px every 185s (my screen lock set @ 3 mins), worst case scenario screen not visibly locked 6 mins.

here essential part of code:

user@somepc:~/bin$ cat ./jiggle.sh #!/bin/bash  while :; xdotool mousemove_relative 1 0 mousemove_relative -- -1 0; sleep 185; done  

then added script "startup programs" , never looked back..