Here's a log of the screen blanking after unactivity, then spontaneously unblanking (it was not locked) with 6.02. I was nowhere near the mouse or the keyboard at that time.
xscreensaver: 16:54:33: checking init file xscreensaver: 16:54:40: XI RawKeyRelease xscreensaver: 16:54:44: XI RawButtonPress 5 xscreensaver: 16:54:47: XI RawKeyPress xscreensaver: 16:55:16: XI RawKeyPress xscreensaver: 16:55:26: XI RawKeyPress xscreensaver: 16:58:28: checking init file xscreensaver: 16:58:28: blanking xscreensaver: 16:58:28: grabbing keyboard on 0x55a: GrabSuccess xscreensaver: 16:58:28: grabbing mouse on 0x55a... GrabSuccess xscreensaver: 16:58:28: pid 1456177: launched xscreensaver-gfx --verbose xscreensaver-gfx: 16:58:28: selecting RANDR events xscreensaver-gfx: 16:58:28: screens in use: 2 xscreensaver-gfx: 16:58:28: 0/0: 1440x2560+0+0 (DP-1) xscreensaver-gfx: 16:58:28: 1/0: 1440x2560+1440+0 (DP-2) xscreensaver-gfx: 16:58:28: blanking xscreensaver-gfx: 16:58:28: 0: X says monitor has powered down; not launching a hack xscreensaver-gfx: 16:58:28: 0: next cycle in 600 sec at 17:08:28 xscreensaver-gfx: 16:58:28: 1: X says monitor has powered down; not launching a hack xscreensaver-gfx: 16:58:28: 1: offsetting cycle time by 300 sec xscreensaver-gfx: 16:58:28: 1: next cycle in 900 sec at 17:13:28 xscreensaver: 17:01:47: checking init file xscreensaver: 17:01:47: unblanking xscreensaver: 17:01:47: pid 1456177: killing xscreensaver-gfx xscreensaver: 17:01:47: ungrabbing mouse xscreensaver: 17:01:47: ungrabbing keyboard xscreensaver-gfx: 17:01:47: SIGTERM: unblanking xscreensaver-gfx: 17:01:47: SIGTERM: exiting xscreensaver: 17:01:47: pid 1456177: xscreensaver-gfx exited with SIGTERM xscreensaver: 17:02:14: XI RawKeyPress xscreensaver: 17:02:17: XI RawKeyPress xscreensaver: 17:02:25: XI RawKeyPress
