Render artifacts in translucency in renders

Hi guys,

I am getting strange dithering kind of artifacts in the leaves of trees I am using. It only seems to be when the leaves appear in front of volumetric fog lights so I don’t know if it’s the leaves materials or the fog itself.
Whatever it is I can’t seem to figure out the problem.
Any suggestions appreciated.

One other observation to note: When I scrub the timeline in the sequencer then I can see the issue but when I stop on a frame the issue seems to get resolved. Is there a quality or optimization setting or cvar that i can adjust to eliminate what might be an optimization technique. I’m after quality, not real time. Using the movie render queue to render.