VolumeLightingSamples are not generated correctly

Lightmass.exe SampleVolume.cpp seems to generate VolumeLightingSamples correctly.
After that, import processing is performed with Lightmass.cpp ImportVolumeSamples (), but it seems that it is not imported correctly.
Level.cpp GetOrCreateMapBuildData () seems suspicious.

Also, the problem seems to occur only if SubLevel_B.umap provided by the licensee is included.
SubLevel_B.umap may be broken.

Is there a way to check if it is broken?

1. Open MainMap.umap.
2. Display VolumeLightingSamples. You can confirm that the SurfaceLightSample has not been generated correctly on the ProblemPlane.
3. Override the Lightmap Resolutions of ProblemPlane, ExpectedPlane, and TriggerSphere with 4.
4. When a light build is performed, VolumeLightingSamples is not generated correctly.