We’ve had the same with the TrueSkyLight for about a year now, we’ve never been able to use it and also have been using a regular Skylight and recapturing, but really isn’t ideal. Recently got the 4.16.2 branch from the Simul git repo and tried it again but it’s the same. Lighting looks fine when in the sunlight, but when in shadows or at night speculars are really strange and our character looks like he’s made of chrome. Would love to figure out what the cause of is so we can use the correct SkyLight.