Pretty much as the subject says, the screensaver keeps activating and locking me out while I'm watching a long video, even while in full-screen. I've been able to find posts discussing this issue in Ubuntu or in earlier (non-LXQt) versions of Lubuntu, but I haven't seen it for 18.10+ yet (gnome-tweaks isn't going to help much here).
Is there any way to prevent this from happening?
(Edit: I had the wrong version listed initially; I'm still seeing the error in 19.04.)