Hammer Bug: light previewing inconsistent

[stann-co]

Describe the bug

3d lighting preview, and 3d lighting preview (raytraced) both behave very inconsistent with lighting. the 2 views appear very different from eachother, and occasion do not show the lighting present at all.

To Reproduce

extract zip, open map in hammer, and notice the big difference in both the lighting previews and the actual map.

Issue Map

epic_map.zip

Expected Behavior

while we can't expect a 1 to 1 preview in the actual game, if atleast the hammer preview could show up consistently it would be a great start

Operating System

windows 10