Lighting glitch that happens at random.

[HighGradeLithium]

Any idea what could be causing the lighting glitch in the pictures? Beams, fire smoke, skylights, etc. all glitch out at random. Can't pin down any exact cause and restarting the game makes it go away until it randomly happens again. Happens with ENB disabled too.

 

Using ELFX for lighting, but never used to have this problem in the past.