Landscape Grass No Longer Casts a Shadow with "Use Landscape Lightmap" Enabled

Landscape Grass No Longer Casts a Shadow with "Use Landscape Lightmap" Enabled. Working as expected in 4.20 CL# 4369336 and 4.21 CL# 4753647

Found in 4.22 CL# 5660361 and 4.23 CL# 5779284

1. Open attached Project
2. Load the "LandscapeGrassLightmapBug" level
3. Look at the landscape grass

Results:
Landscape grass does not have any lightmap but uses volumetric samples which results lower quality shadows.

Expected:
Grass would be casting a shadow.