Xscreen 保護程序未鎖定使用者

在我新安裝的 Xscreen 保護程序中，當螢幕保護程序啟動時，它不會鎖定使用者。任何想法有什麼問題嗎？

timeout:    0:03:00
cycle:      0:10:00
lock:       True       <--------LOOKS GOOD HERE
lockTimeout:    0:03:00   <--------LOOKS GOOD HERE
passwdTimeout:  0:00:30
visualID:   default
installColormap:    True
verbose:    False
timestamp:  True
splash:     True
splashDuration: 0:00:05
demoCommand:    xscreensaver-demo
prefsCommand:   xscreensaver-demo -prefs
nice:       10
memoryLimit:    0
fade:       True
unfade:     True
fadeSeconds:    0:00:02
fadeTicks:  20
captureStderr:  True
ignoreUninstalledPrograms:False
font:       *-medium-r-*-140-*-m-*
dpmsEnabled:    False
dpmsQuickOff:   False
dpmsStandby:    2:00:00
dpmsSuspend:    2:00:00
dpmsOff:    4:00:00
grabDesktopImages:  False
grabVideoFrames:    False
chooseRandomImages: False
imageDirectory: 

人 xscreensaver 展示：

  Lock Screen After
      This  controls  the length of the ``grace period'' between when the
      screensaver activates, and when the  screen  becomes  locked.   For
      example,  if this is 5 minutes, and Blank After is 10 minutes, then
      after 10 minutes, the screen would blank.  If there was user activ‐
      ity  at  12  minutes, no password would be required to un-blank the
      screen.  But, if there was user activity at  15  minutes  or  later
      (that  is, Lock Screen After minutes after activation) then a pass‐
      word would be required.  The default is 0, meaning that if  locking
      is  enabled, then a password will be required as soon as the screen
      blanks.

引用自：https://unix.stackexchange.com/questions/323477