It seems to have started with Beta 2.11-01. Here's pictures taken from three consecutive restarts of The Outpost, viewpoint coordinates (1007, 355, -63), (45, -136, 0) in a fresh install of Beta 2.11-01. All of these candles are meant to be extinguished.
The problem is very intermittent. Sometimes it won't happen at all just by restarting the mission and you have to quit and re-enter Dark Mod to get the bug to show. I couldn't replicate it at all in release 2.10.