Try manualy place volumetric lightmaps by “Volumetric Lightmap Density Volume”.
This volume exist in UE 4.19.2.
Other versions I did not check.
Other same:
- Volumetric Lightmap sample and Indoor ArchViz Scene not working at all - Rendering - Unreal Engine Forums
- Working with the new Lightmap volume, I have a Question. - Rendering - Unreal Engine Forums
“Volumetric Lightmap Density Volume”:
Sreenshot from engine with this volume and volumetric lightmaps:
