Hi Eric,
I conducted the tests you suggested previously, and unfortunately results were the same with the marching black ants still present when Realtime is turned on afterwards. I’ve been trying Medium, Preview, and Production qualities for lighting:
Test 1: I selected all my lights and turned off Cast Shadows, rebuilt lighting.
Test 2: I deleted both sphere capture actors in my main hallway, still kept all lights with Cast Shadows turned OFF. Rebuilt lighting.
Test 3: Deleted sphere capture actors but kept original light settings (some with Cast Shadows on, some with off), rebaked lighting.
Thanks,
DarKris3