Override Screen Lock on playing videos through VLC player in full screen mode or other applications in presentation mode.
Which version of Lubuntu?
I don’t lock the screen but I do have a screensaver and it is suspended while watching a full screen movie with VLC.
On my 19.04
Is there any settings to configure?
VLC should handle this for you if you have it set to the default settings, which includes the option to disable the screensaver:
If you’re still having problems, make sure that in Power Management settings, you have the idleness watcher set to do nothing, or just unenable it:
Secondly, in the Screensaver settings, make sure that the lock screen option is not set. Also, you can disable the screensaver here, too: