CPU Lightmass GI breaks when deleting cache

Summary

The last fix(es) for UE 5.8.1 for Substrate worked initially where CPU lightmass baked GI correctly as well.
When deleting the projects DerivedDataCache/Intermediate/Saved and global caches (Appdata/Unreal Engine) baking GI is not possible anymore with Substrate enabled.

What Type of Bug are you experiencing?

Rendering (Graphics / Niagara)

Steps to Reproduce

  • delete folder Appdata/Unreal Engine to clear all global caches if they are stored there
  • create a new project
  • project settings: allow static lighting, substrate enabled
  • place white boxes and a splotlight, set all lighting to static or stationary. bake lighting with cpu lightmass

Expected Result

GI is visible. With legacy material system it works.

Observed Result

no GI is correctly baked, especially for small lights its not visible at all.

Affects Versions

5.8

Platform(s)

Windows

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The status of UE-391106 changed to ‘Needs Triage’. We are routing this to the appropriate team for investigation.