Small cloud like artifacts in Volumetric Fog

Huge road block in an interior scene. Using UE 4.27p4.

Lighting a large interior scene using only a dozen overhead spotlights and a skylight, all Stationary. No RayTracing

Unable to figure out why my volumetric fog is disaplaying strange 3d cloud like artifacts. Tried playing with Exponential heightFog settings but nothing seems to make a difference.

Seems to be related to the density of my VolumetricLightmapDensity Volume. The more dense, the more cloud artifacts.

Can any lighting experts chime in?

Anyone??

i have the same issue any solutions yet?